{"id":148,"date":"2017-03-17T11:28:38","date_gmt":"2017-03-17T11:28:38","guid":{"rendered":"http:\/\/codeinsightacademy.com\/blog\/?p=148"},"modified":"2017-05-11T15:30:13","modified_gmt":"2017-05-11T15:30:13","slug":"collections","status":"publish","type":"post","link":"https:\/\/codeinsightacademy.com\/blog\/java\/collections\/","title":{"rendered":"Collections"},"content":{"rendered":"

 <\/p>\n

ArrayList list = new ArrayList();\r\n        list.add(\"h\");\r\n        list.add(\"e\");\r\n        list.add(\"l\");\r\n        list.add(\"l\");\r\n        list.add(\"o\");\r\n\r\n        for (int i = 1; i < 10; i++) {\r\n            list.add(i);\r\n        }\r\n\r\n        Iterator it = list.iterator();\r\n\r\n        while (it.hasNext()) {\r\n            out.println(it.next() + \"<br\/>\");\r\n        }\r\n\r\n        HashSet hs = new HashSet();\r\n        hs.add(\"A\");\r\n        hs.add(\"B\");\r\n        hs.add(\"C\");\r\n        hs.add(\"C\");\r\n        hs.add(\"C\");\r\n\r\n        HashMap hm = new HashMap();\r\n        hm.put(\"a\", \"A\");\r\n        hm.put(\"b\", \"B\");\r\n\r\n        Iterator its = hs.iterator();\r\n\r\n        while (its.hasNext()) {\r\n            out.println(its.next() + \"<br\/>\");\r\n        }\r\n\r\n        Iterator itr = hm.entrySet().iterator();\r\n\r\n        while (itr.hasNext()) {\r\n            Map.Entry pair = (Map.Entry) itr.next();\r\n            out.println(pair.getKey() + \" => \" + pair.getValue() + \"<br\/>\");\r\n        }\r\n\r\n        String[] strarr = new String[10];\r\n\r\n        for (int i = 0; i < 10; i++) {\r\n            strarr[i] = \"abc\" + i;\r\n        }\r\n\r\n        for (String valu : strarr) {\r\n            out.println(valu);\r\n        }\r\n<\/pre>\n
 
\nRef:<\/p>\n
    \n
  1. http:\/\/stackoverflow.com\/questions\/85190\/how-does-the-java-for-each-loop-work<\/li>\n
  2. http:\/\/stackoverflow.com\/questions\/4131655\/what-is-the-difference-between-lists-arraylists-maps-hashmaps-collections-et<\/li>\n
  3. https:\/\/www.quora.com\/What-is-the-difference-between-a-Set-and-a-Map-in-Java<\/li>\n
  4. http:\/\/stackoverflow.com\/questions\/1066589\/iterate-through-a-hashmap<\/li>\n
  5. http:\/\/stackoverflow.com\/questions\/1200621\/how-to-declare-an-array-in-java<\/li>\n
  6. http:\/\/stackoverflow.com\/questions\/1665834\/how-can-i-initialize-a-string-array-with-length-0-in-java<\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"
      ArrayList list = new ArrayList(); list.add(“h”); list.add(“e”); list.add(“l”); list.add(“l”); list.add(“o”); for (int i = 1; i < 10; i++) { list.add(i); } Iterator it = list.iterator(); while (it.hasNext()) { out.println(it.next() + “<br\/>”); } HashSet hs = new HashSet(); hs.add(“A”); hs.add(“B”); hs.add(“C”); hs.add(“C”); hs.add(“C”); HashMap hm = new HashMap(); hm.put(“a”, “A”); hm.put(“b”, “B”); Iterator its […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[3],"tags":[],"_links":{"self":[{"href":"https:\/\/codeinsightacademy.com\/blog\/wp-json\/wp\/v2\/posts\/148"}],"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=148"}],"version-history":[{"count":5,"href":"https:\/\/codeinsightacademy.com\/blog\/wp-json\/wp\/v2\/posts\/148\/revisions"}],"predecessor-version":[{"id":250,"href":"https:\/\/codeinsightacademy.com\/blog\/wp-json\/wp\/v2\/posts\/148\/revisions\/250"}],"wp:attachment":[{"href":"https:\/\/codeinsightacademy.com\/blog\/wp-json\/wp\/v2\/media?parent=148"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/codeinsightacademy.com\/blog\/wp-json\/wp\/v2\/categories?post=148"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/codeinsightacademy.com\/blog\/wp-json\/wp\/v2\/tags?post=148"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}