{"id":2533,"date":"2023-06-25T08:10:41","date_gmt":"2023-06-25T08:10:41","guid":{"rendered":"https:\/\/codeinsightacademy.com\/blog\/?p=2533"},"modified":"2023-06-25T08:10:42","modified_gmt":"2023-06-25T08:10:42","slug":"php-crash-course","status":"publish","type":"post","link":"https:\/\/codeinsightacademy.com\/blog\/php\/php-crash-course\/","title":{"rendered":"PHP Crash Course"},"content":{"rendered":"\n<h2 class=\"has-text-align-center\">Basics<\/h2>\n\n\n\n<ul><li>Example 1: Printing &#8220;Hello, World!&#8221; using <code>echo<\/code>:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   echo \"Hello, World!\";<\/pre>\n\n\n\n<ul><li>Example 2: Assigning and displaying variables:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $name = \"John Doe\";\n   echo \"My name is \" . $name;<\/pre>\n\n\n\n<ul><li>Example 3: Writing comments in PHP code:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   \/\/ This is a single-line comment\n\n   \/*\n   This is a\n   multi-line comment\n   *\/<\/pre>\n\n\n\n<ul><li>Example 4: Using the <code>print<\/code> statement:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   print \"Welcome to PHP\";<\/pre>\n\n\n\n<ul><li>Example 5: Getting the current date and time:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $currentDate = date(\"Y-m-d H:i:s\");\n   echo \"Current date and time: \" . $currentDate;<\/pre>\n\n\n\n<h2 class=\"has-text-align-center\">Variables and Constants<\/h2>\n\n\n\n<ul><li>Example 1: Declaring and using variables:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $name = \"John Doe\";\n   $age = 25;\n   $salary = 5000.50;\n\n   echo \"Name: \" . $name . \", Age: \" . $age . \", Salary: $\" . $salary;<\/pre>\n\n\n\n<ul><li>Example 2: Defining and using constants:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   define(\"PI\", 3.14);\n   echo \"The value of PI is: \" . PI;<\/pre>\n\n\n\n<ul><li>Example 3: Variable scope (local and global):<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $globalVariable = \"I am a global variable\";\n\n   function myFunction() {\n       $localVariable = \"I am a local variable\";\n       echo $localVariable;\n       echo $GLOBALS['globalVariable'];\n   }\n\n   myFunction();<\/pre>\n\n\n\n<ul><li>Example 4: Variable interpolation:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $name = \"John Doe\";\n   echo \"My name is $name\";<\/pre>\n\n\n\n<ul><li>Example 5: Constants case sensitivity:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   define(\"MY_CONSTANT\", \"Hello\");\n   echo MY_CONSTANT;\n   echo my_constant;<\/pre>\n\n\n\n<h2 class=\"has-text-align-center\">Operators<\/h2>\n\n\n\n<ul><li>Example 1: Arithmetic operators:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $num1 = 10;\n   $num2 = 5;\n\n   echo $num1 + $num2; \/\/ Addition\n   echo $num1 - $num2; \/\/ Subtraction\n   echo $num1 * $num2; \/\/ Multiplication\n   echo $num1 \/ $num2; \/\/ Division\n   echo $num1 % $num2; \/\/ Modulo<\/pre>\n\n\n\n<ul><li>Example 2: Assignment operators:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $num = 10;\n   $num += 5; \/\/ Equivalent to $num = $num + 5;\n   echo $num;\n\n   $str = \"Hello\";\n   $str .= \" World\"; \/\/ Equivalent to $str = $str . \" World\";\n   echo $str;<\/pre>\n\n\n\n<ul><li>Example 3: Comparison operators:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $num1 = 10;\n   $num2 = 5;\n\n   var_dump($num1 == $num2);  \/\/ Equal to\n   var_dump($num1 != $num2);  \/\/ Not equal to\n   var_dump($num1 > $num2);   \/\/ Greater than\n   var_dump($num1 &lt; $num2);   \/\/ Less than\n   var_dump($num1 >= $num2);  \/\/ Greater than or equal to\n   var_dump($num1 &lt;= $num\n\n2);  \/\/ Less than or equal to<\/pre>\n\n\n\n<ul><li>Example 4: Logical operators:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $num1 = 10;\n   $num2 = 5;\n   $num3 = 7;\n\n   var_dump($num1 > $num2 &amp;&amp; $num1 &lt; $num3);   \/\/ Logical AND\n   var_dump($num1 > $num2 || $num1 > $num3);   \/\/ Logical OR\n   var_dump(!($num1 > $num2));                  \/\/ Logical NOT<\/pre>\n\n\n\n<ul><li>Example 5: String operators:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $str1 = \"Hello\";\n   $str2 = \"World\";\n\n   echo $str1 . $str2;   \/\/ Concatenation\n   echo $str1 .= $str2;  \/\/ Concatenation and assignment<\/pre>\n\n\n\n<h2 class=\"has-text-align-center\">Conditionals<\/h2>\n\n\n\n<ul><li>Example 1: If-else statement:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $num = 10;\n\n   if ($num > 0) {\n       echo \"The number is positive\";\n   } else {\n       echo \"The number is not positive\";\n   }<\/pre>\n\n\n\n<ul><li>Example 2: Switch case statement:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $day = \"Monday\";\n\n   switch ($day) {\n       case \"Monday\":\n           echo \"Today is Monday\";\n           break;\n       case \"Tuesday\":\n           echo \"Today is Tuesday\";\n           break;\n       default:\n           echo \"Today is not Monday or Tuesday\";\n   }<\/pre>\n\n\n\n<ul><li>Example 3: Ternary operator:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $num = 10;\n\n   $result = ($num % 2 == 0) ? \"Even\" : \"Odd\";\n   echo $result;<\/pre>\n\n\n\n<ul><li>Example 4: Multiple conditions in if statement:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $num = 10;\n\n   if ($num > 0 &amp;&amp; $num &lt; 20) {\n       echo \"The number is between 0 and 20\";\n   }<\/pre>\n\n\n\n<ul><li>Example 5: Nested if-else statements:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $num = 10;\n\n   if ($num > 0) {\n       if ($num &lt; 20) {\n           echo \"The number is between 0 and 20\";\n       }\n   }<\/pre>\n\n\n\n<h2 class=\"has-text-align-center\">Loop Constructs<\/h2>\n\n\n\n<ul><li>Example 1: For loop:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   for ($i = 1; $i &lt;= 5; $i++) {\n       echo $i . \" \";\n   }<\/pre>\n\n\n\n<ul><li>Example 2: While loop:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $i = 1;\n\n   while ($i &lt;= 5) {\n       echo $i . \" \";\n       $i++;\n   }<\/pre>\n\n\n\n<ul><li>Example 3: Do-while loop:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $i = 1;\n\n   do {\n       echo $i . \" \";\n       $i++;\n   } while ($i &lt;= 5);<\/pre>\n\n\n\n<ul><li>Example 4: Foreach loop with an array:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $numbers = [1, 2, 3, 4, 5];\n\n   foreach ($numbers as $number) {\n       echo $number . \" \";\n   }<\/pre>\n\n\n\n<ul><li>Example 5: Loop control statements (break and continue):<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   for ($i = 1; $i &lt;= 10; $i++) {\n       if ($i == 5) {\n           break;      \/\/ Exit the loop\n       }\n\n       if ($i % 2 == 0) {\n           continue;   \/\/ Skip the rest of the iteration\n\n\n }\n\n       echo $i . \" \";\n   }<\/pre>\n\n\n\n<h2 class=\"has-text-align-center\">Arrays<\/h2>\n\n\n\n<ul><li>Example 1: Creating an indexed array:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $fruits = [\"Apple\", \"Banana\", \"Orange\"];<\/pre>\n\n\n\n<ul><li>Example 2: Accessing array elements:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $fruits = [\"Apple\", \"Banana\", \"Orange\"];\n   echo $fruits[0];  \/\/ Output: Apple<\/pre>\n\n\n\n<ul><li>Example 3: Modifying array elements:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $fruits = [\"Apple\", \"Banana\", \"Orange\"];\n   $fruits[1] = \"Mango\";<\/pre>\n\n\n\n<ul><li>Example 4: Counting array elements:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $fruits = [\"Apple\", \"Banana\", \"Orange\"];\n   $count = count($fruits);\n   echo $count;  \/\/ Output: 3<\/pre>\n\n\n\n<ul><li>Example 5: Searching for a value in an array:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $fruits = [\"Apple\", \"Banana\", \"Orange\"];\n   $index = array_search(\"Banana\", $fruits);\n   echo $index;  \/\/ Output: 1<\/pre>\n\n\n\n<h2 class=\"has-text-align-center\">Multi-Dimensional Arrays<\/h2>\n\n\n\n<ul><li>Example 1: Creating a 2D array:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $matrix = [\n       [1, 2, 3],\n       [4, 5, 6],\n       [7, 8, 9]\n   ];<\/pre>\n\n\n\n<ul><li>Example 2: Accessing elements in a 2D array:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $matrix = [\n       [1, 2, 3],\n       [4, 5, 6],\n       [7, 8, 9]\n   ];\n\n   echo $matrix[1][2];  \/\/ Output: 6<\/pre>\n\n\n\n<ul><li>Example 3: Modifying elements in a 2D array:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $matrix = [\n       [1, 2, 3],\n       [4, 5, 6],\n       [7, 8, 9]\n   ];\n\n   $matrix[2][1] = 10;<\/pre>\n\n\n\n<ul><li>Example 4: Counting elements in a 2D array:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $matrix = [\n       [1, 2, 3],\n       [4, 5, 6],\n       [7, 8, 9]\n   ];\n\n   $count = count($matrix, COUNT_RECURSIVE);\n   echo $count;  \/\/ Output: 9<\/pre>\n\n\n\n<ul><li>Example 5: Searching for a value in a 2D array:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $matrix = [\n       [1, 2, 3],\n       [4, 5, 6],\n       [7, 8, 9]\n   ];\n\n   $index = array_search(6, array_merge(...$matrix));\n   echo $index;  \/\/ Output: 5<\/pre>\n\n\n\n<h2 class=\"has-text-align-center\">Associative Arrays<\/h2>\n\n\n\n<ul><li>Example 1: Creating an associative array:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $student = [\n       \"name\" => \"John Doe\",\n       \"age\" => 20,\n       \"city\" => \"New York\"\n   ];<\/pre>\n\n\n\n<ul><li>Example 2: Accessing values in an associative array:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $student = [\n       \"name\" => \"John Doe\",\n       \"age\" => 20,\n       \"city\" => \"New York\"\n   ];\n\n   echo $student[\"name\"]; \n\n \/\/ Output: John Doe<\/pre>\n\n\n\n<ul><li>Example 3: Modifying values in an associative array:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $student = [\n       \"name\" => \"John Doe\",\n       \"age\" => 20,\n       \"city\" => \"New York\"\n   ];\n\n   $student[\"age\"] = 21;<\/pre>\n\n\n\n<ul><li>Example 4: Counting elements in an associative array:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $student = [\n       \"name\" => \"John Doe\",\n       \"age\" => 20,\n       \"city\" => \"New York\"\n   ];\n\n   $count = count($student);\n   echo $count;  \/\/ Output: 3<\/pre>\n\n\n\n<ul><li>Example 5: Checking if a key exists in an associative array:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $student = [\n       \"name\" => \"John Doe\",\n       \"age\" => 20,\n       \"city\" => \"New York\"\n   ];\n\n   $exists = array_key_exists(\"age\", $student);\n   echo $exists;  \/\/ Output: 1 (true)<\/pre>\n\n\n\n<h2 class=\"has-text-align-center\">Array of Associative Arrays<\/h2>\n\n\n\n<ul><li>Example 1: Creating an array of associative arrays:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $students = [\n       [\n           \"name\" => \"John Doe\",\n           \"age\" => 20,\n           \"city\" => \"New York\"\n       ],\n       [\n           \"name\" => \"Jane Smith\",\n           \"age\" => 22,\n           \"city\" => \"Los Angeles\"\n       ],\n       [\n           \"name\" => \"Mike Johnson\",\n           \"age\" => 19,\n           \"city\" => \"Chicago\"\n       ]\n   ];<\/pre>\n\n\n\n<ul><li>Example 2: Accessing values in an array of associative arrays:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $students = [\n       [\n           \"name\" => \"John Doe\",\n           \"age\" => 20,\n           \"city\" => \"New York\"\n       ],\n       [\n           \"name\" => \"Jane Smith\",\n           \"age\" => 22,\n           \"city\" => \"Los Angeles\"\n       ],\n       [\n           \"name\" => \"Mike Johnson\",\n           \"age\" => 19,\n           \"city\" => \"Chicago\"\n       ]\n   ];\n\n   echo $students[1][\"name\"];  \/\/ Output: Jane Smith<\/pre>\n\n\n\n<ul><li>Example 3: Modifying values in an array of associative arrays:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $students = [\n       [\n           \"name\" => \"John Doe\",\n           \"age\" => 20,\n           \"city\" => \"New York\"\n       ],\n       [\n           \"name\" => \"Jane Smith\",\n           \"age\" => 22,\n           \"city\" => \"Los Angeles\"\n       ],\n       [\n           \"name\" => \"Mike Johnson\",\n           \"age\" => 19,\n           \"city\" => \"Chicago\"\n       ]\n   ];\n\n   $students[2][\"age\"] = 20;<\/pre>\n\n\n\n<ul><li>Example 4: Counting elements in an array of associative arrays:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $students = [\n       [\n           \"name\" => \"John Doe\",\n           \"age\" => 20,\n           \"city\" => \"New York\"\n       ],\n       [\n           \"name\" => \"Jane Smith\",\n           \"age\" => 22,\n           \"city\" => \"Los Angeles\"\n       ],\n       [\n           \"name\" => \"Mike Johnson\",\n           \"age\" => 19,\n           \"city\" => \"Chicago\"\n       ]\n   ];\n\n   $count = count($students);\n   echo $count;  \/\/ Output: 3<\/pre>\n\n\n\n<ul><li>Example 5: Searching for a value in an array of associative arrays:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $students = [\n       [\n           \"name\" => \"John Doe\",\n           \"age\" => 20,\n           \"city\" => \"New York\"\n       ],\n       [\n           \"name\" => \"Jane Smith\",\n           \"age\" => 22,\n           \"city\" => \"Los Angeles\"\n       ],\n       [\n           \"name\" => \"Mike Johnson\",\n           \"age\" => 19,\n           \"city\" => \"Chicago\"\n       ]\n   ];\n\n   $index = array_search(\"Los Angeles\", array_column($students, \"city\"));\n   echo $index;  \/\/ Output: 1<\/pre>\n\n\n\n<h2 class=\"has-text-align-center\">Functions<\/h2>\n\n\n\n<ul><li>Example 1: Creating a function:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   function sayHello() {\n       echo \"Hello, World!\";\n   }\n\n   sayHello();<\/pre>\n\n\n\n<ul><li>Example 2: Function with parameters:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   function greet($name) {\n       echo \"Hello, \" . $name . \"!\";\n   }\n\n   greet(\"John\");<\/pre>\n\n\n\n<ul><li>Example 3: Returning a value from a function:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   function add($num1, $num2) {\n       return $num1 + $num2;\n   }\n\n   $result = add(3, 5);\n   echo $result;  \/\/ Output: 8<\/pre>\n\n\n\n<ul><li>Example 4: Function with default parameter value:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   function greet($name = \"Guest\") {\n       echo \"Hello, \" . $name . \"!\";\n   }\n\n   greet();       \/\/ Output: Hello, Guest!\n   greet(\"John\"); \/\/ Output: Hello, John!<\/pre>\n\n\n\n<ul><li>Example 5: Recursive function:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   function factorial($num) {\n       if ($num &lt;= 1) {\n           return 1;\n       }\n\n       return $num * factorial($num - 1);\n   }\n\n   $result = factorial(5);\n   echo $result;  \/\/ Output: 120<\/pre>\n\n\n\n<h2 class=\"has-text-align-center\">Classes<\/h2>\n\n\n\n<ul><li>Example 1: Creating a class:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   class Person {\n       public $name;\n       public $age;\n\n       public function sayHello() {\n           echo \"Hello, my name is \" . $this->name . \" and I am \" . $this->age . \" years old.\";\n       }\n   }\n\n   $person = new Person();\n   $person->name = \"John\";\n   $person->age = 25;\n   $person->sayHello();<\/pre>\n\n\n\n<ul><li>Example 2: Constructors and property accessors:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   class Person {\n       private $name;\n       private $age;\n\n       public function __construct($name, $age) {\n           $this->name = $name;\n           $this->age = $age;\n       }\n\n       public function getName() {\n           return $this->name;\n       }\n\n       public function getAge() {\n           return $this->age;\n       }\n   }\n\n   $person = new Person(\"John\", 25);\n   echo $person->getName();  \/\/ Output: John\n   echo $person->getAge();   \/\/ Output: 25<\/pre>\n\n\n\n<ul><li>Example 3: Inheritance:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   class Animal {\n       public function makeSound() {\n           echo \"The animal makes a sound.\";\n       }\n   }\n\n   class Dog extends Animal {\n       public function makeSound() {\n           echo \"The dog barks.\";\n       }\n   }\n\n   $dog = new Dog();\n   $dog->makeSound();  \/\/ Output: The dog barks.<\/pre>\n\n\n\n<ul><li>Example<\/li><\/ul>\n\n\n\n<p>4: Static properties and methods:<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   class MathUtils {\n       public static $pi = 3.14159;\n\n       public static function square($num) {\n           return $num * $num;\n       }\n   }\n\n   echo MathUtils::$pi;            \/\/ Output: 3.14159\n   echo MathUtils::square(5);      \/\/ Output: 25<\/pre>\n\n\n\n<ul><li>Example 5: Abstract classes and interfaces:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   abstract class Animal {\n       abstract public function makeSound();\n   }\n\n   interface CanFly {\n       public function fly();\n   }\n\n   class Bird extends Animal implements CanFly {\n       public function makeSound() {\n           echo \"The bird chirps.\";\n       }\n\n       public function fly() {\n           echo \"The bird is flying.\";\n       }\n   }\n\n   $bird = new Bird();\n   $bird->makeSound();  \/\/ Output: The bird chirps.\n   $bird->fly();        \/\/ Output: The bird is flying.<\/pre>\n\n\n\n<h2 class=\"has-text-align-center\">File Handling<\/h2>\n\n\n\n<ul><li>Example 1: Reading from a file:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $file = fopen(\"data.txt\", \"r\");\n   while (!feof($file)) {\n       $line = fgets($file);\n       echo $line;\n   }\n   fclose($file);<\/pre>\n\n\n\n<ul><li>Example 2: Writing to a file:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $file = fopen(\"data.txt\", \"w\");\n   fwrite($file, \"Hello, World!\");\n   fclose($file);<\/pre>\n\n\n\n<ul><li>Example 3: Appending to a file:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $file = fopen(\"data.txt\", \"a\");\n   fwrite($file, \"New content\");\n   fclose($file);<\/pre>\n\n\n\n<ul><li>Example 4: Checking if a file exists:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   if (file_exists(\"data.txt\")) {\n       echo \"File exists.\";\n   } else {\n       echo \"File does not exist.\";\n   }<\/pre>\n\n\n\n<ul><li>Example 5: Deleting a file:<\/li><\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   unlink(\"data.txt\");<\/pre>\n\n\n\n<h2 class=\"has-text-align-center\">Database Connection (MySQL)<\/h2>\n\n\n\n<ol><li>Connecting to the database:<\/li><\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">$servername = \"localhost\";\n$username = \"your_username\";\n$password = \"your_password\";\n$dbname = \"your_database\";\n\ntry {\n    $conn = new PDO(\"mysql:host=$servername;dbname=$dbname\", $username, $password);\n    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);\n    echo \"Connected successfully\";\n} catch (PDOException $e) {\n    echo \"Connection failed: \" . $e->getMessage();\n}<\/pre>\n\n\n\n<ol start=\"2\"><li>Selecting all users from the &#8220;users&#8221; table:<\/li><\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">try {\n    $stmt = $conn->query(\"SELECT * FROM users\");\n    $users = $stmt->fetchAll(PDO::FETCH_ASSOC);\n\n    foreach ($users as $user) {\n        echo \"ID: \" . $user['id'] . \" - Name: \" . $user['name'] . \" - Age: \" . $user['age'] . \" - City: \" . $user['city'] . \" - Salary: \" . $user['salary'] . \"&lt;br>\";\n    }\n} catch (PDOException $e) {\n    echo \"Error: \" . $e->getMessage();\n}<\/pre>\n\n\n\n<ol start=\"3\"><li>Deleting a user from the &#8220;users&#8221; table:<\/li><\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">try {\n    $id = 1;\n\n    $stmt = $conn->prepare(\"DELETE FROM users WHERE id = :id\");\n    $stmt->bindParam(':id', $id);\n    $stmt->execute();\n\n    echo \"User deleted successfully\";\n} catch (PDOException $e) {\n    echo \"Error: \" . $e->getMessage();\n}<\/pre>\n\n\n\n<ol start=\"4\"><li>Adding a new user to the &#8220;users&#8221; table:<\/li><\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">try {\n    $name = \"John Doe\";\n    $age = 25;\n    $city = \"New York\";\n    $salary = 5000;\n\n    $stmt = $conn->prepare(\"INSERT INTO users (name, age, city, salary) VALUES (:name, :age, :city, :salary)\");\n    $stmt->bindParam(':name', $name);\n    $stmt->bindParam(':age', $age);\n    $stmt->bindParam(':city', $city);\n    $stmt->bindParam(':salary', $salary);\n    $stmt->execute();\n\n    echo \"New user added successfully\";\n} catch (PDOException $e) {\n    echo \"Error: \" . $e->getMessage();\n}<\/pre>\n\n\n\n<ol start=\"5\"><li>Fetching a single user from the &#8220;users&#8221; table:<\/li><\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">try {\n    $id = 1;\n\n    $stmt = $conn->prepare(\"SELECT * FROM users WHERE id = :id\");\n    $stmt->bindParam(':id', $id);\n    $stmt->execute();\n\n    $user = $stmt->fetch(PDO::FETCH_ASSOC);\n\n    if ($user) {\n        echo \"ID: \" . $user['id'] . \" - Name: \" . $user['name'] . \" - Age: \" . $user['age'] . \" - City: \" . $user['city'] . \" - Salary: \" . $user['salary'];\n    } else {\n        echo \"User not found\";\n    }\n} catch (PDOException $e) {\n    echo \"Error: \" . $e->getMessage();\n}<\/pre>\n\n\n\n<p>Remember to replace &#8220;your_username&#8221;, &#8220;your_password&#8221;, and &#8220;your_database&#8221; with your actual MySQL credentials and database name. Additionally, ensure that PDO extension is enabled in your PHP configuration.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Basics Example 1: Printing &#8220;Hello, World!&#8221; using echo: Example 2: Assigning and displaying variables: Example 3: Writing comments in PHP code: Example 4: Using the print statement: Example 5: Getting the current date and time: Variables and Constants Example 1: Declaring and using variables: Example 2: Defining and using constants: Example 3: Variable scope (local [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[4],"tags":[],"_links":{"self":[{"href":"https:\/\/codeinsightacademy.com\/blog\/wp-json\/wp\/v2\/posts\/2533"}],"collection":[{"href":"https:\/\/codeinsightacademy.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/codeinsightacademy.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/codeinsightacademy.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/codeinsightacademy.com\/blog\/wp-json\/wp\/v2\/comments?post=2533"}],"version-history":[{"count":1,"href":"https:\/\/codeinsightacademy.com\/blog\/wp-json\/wp\/v2\/posts\/2533\/revisions"}],"predecessor-version":[{"id":2534,"href":"https:\/\/codeinsightacademy.com\/blog\/wp-json\/wp\/v2\/posts\/2533\/revisions\/2534"}],"wp:attachment":[{"href":"https:\/\/codeinsightacademy.com\/blog\/wp-json\/wp\/v2\/media?parent=2533"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/codeinsightacademy.com\/blog\/wp-json\/wp\/v2\/categories?post=2533"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/codeinsightacademy.com\/blog\/wp-json\/wp\/v2\/tags?post=2533"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}