From 63504d14ae94ef37e774d00c5540a6eb6296e414 Mon Sep 17 00:00:00 2001 From: Tejas Pundpal <96496782+tejaspundpal@users.noreply.github.com> Date: Fri, 25 Oct 2024 21:32:49 +0530 Subject: [PATCH] Create LearnHashMap.java --- Java/LearnHashMap.java | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) create mode 100644 Java/LearnHashMap.java diff --git a/Java/LearnHashMap.java b/Java/LearnHashMap.java new file mode 100644 index 0000000..f0b5507 --- /dev/null +++ b/Java/LearnHashMap.java @@ -0,0 +1,31 @@ +import javax.swing.text.html.parser.Entity; +import java.util.*; +public class LearnHashMap +{ + public static void main(String[] args) { + Map numbers = new HashMap<>(); + numbers.put("one",1); + numbers.put("five",5); + numbers.put("two",2); + numbers.put("three",3); + + //numbers.put("two",22); ------> override the old value + //numbers.putIfAbsent("two",22); + + System.out.println(numbers); + for(Map.Entry e: numbers.entrySet()){ + System.out.println(e); + } +// for(Map.Entry e: numbers.entrySet()){ +// System.out.println(e.getKey()); +// System.out.println(e.getValue()); +// } + for(String key: numbers.keySet()){ + System.out.println(key); + } + System.out.println(numbers.containsKey("one")); + + numbers.replace("one",1,11); + System.out.println(numbers); + } +}