74 lines
2.3 KiB
Java
74 lines
2.3 KiB
Java
package com.baeldung.map.iteration;
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import java.util.HashMap;
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import java.util.Iterator;
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import java.util.Map;
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public class MapIteration {
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public static void main(String[] args) {
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MapIteration mapIteration = new MapIteration();
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Map<String, Integer> map = new HashMap<>();
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map.put("One", 1);
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map.put("Three", 3);
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map.put("Two", 2);
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System.out.println("Iterating Keys of Map Using KeySet");
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mapIteration.iterateKeys(map);
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System.out.println("Iterating Map Using Entry Set");
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mapIteration.iterateUsingEntrySet(map);
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System.out.println("Iterating Using Iterator and Map Entry");
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mapIteration.iterateUsingIteratorAndEntry(map);
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System.out.println("Iterating Using KeySet and For Each");
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mapIteration.iterateUsingKeySetAndForeach(map);
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System.out.println("Iterating Map Using Lambda Expression");
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mapIteration.iterateUsingLambda(map);
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System.out.println("Iterating Using Stream API");
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mapIteration.iterateUsingStreamAPI(map);
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}
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public void iterateUsingEntrySet(Map<String, Integer> map) {
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for (Map.Entry<String, Integer> entry : map.entrySet()) {
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System.out.println(entry.getKey() + ":" + entry.getValue());
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}
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}
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public void iterateUsingLambda(Map<String, Integer> map) {
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map.forEach((k, v) -> System.out.println((k + ":" + v)));
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}
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public void iterateUsingIteratorAndEntry(Map<String, Integer> map) {
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Iterator<Map.Entry<String, Integer>> iterator = map.entrySet()
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.iterator();
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while (iterator.hasNext()) {
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Map.Entry<String, Integer> pair = iterator.next();
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System.out.println(pair.getKey() + ":" + pair.getValue());
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}
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}
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public void iterateUsingKeySetAndForeach(Map<String, Integer> map) {
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for (String key : map.keySet()) {
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System.out.println(key + ":" + map.get(key));
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}
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}
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public void iterateUsingStreamAPI(Map<String, Integer> map) {
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map.entrySet()
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.stream()
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.forEach(e -> System.out.println(e.getKey() + ":" + e.getValue()));
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}
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public void iterateKeys(Map<String, Integer> map) {
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for (String key : map.keySet()) {
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System.out.println(key);
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}
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}
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} |