最近在看java集合框架部分的内容,总结一下遍历集合元素的几种方式,供参考。
package com.js.general; import java.util.Collection; import java.util.HashSet; /** * Java8为Iterable接口新增了一个forEach()方法,可用于遍历集合元素 * @author jiangs * */ public class CollectionEach { public static void main(String[] args) { Collection<String> books = new HashSet<>(); books.add("深入了解JVM虚拟机1"); books.add("深入了解JVM虚拟机2"); books.add("深入了解JVM虚拟机3"); books.add("深入了解JVM虚拟机4"); books.add("深入了解JVM虚拟机5"); // System.out.println(books.add("深入了解JVM虚拟机")); //collection不允许重复的元素,这边将返回false books.forEach(obj ->System.out.println("遍历集合元素:"+obj)); } } package com.js.general; import java.util.Collection; import java.util.HashSet; public class ForEachTest { public static void main(String[] args) { Collection<String> books = new HashSet<>(); books.add("深入了解JVM虚拟机1"); books.add("深入了解JVM虚拟机2"); books.add("深入了解JVM虚拟机3"); books.add("深入了解JVM虚拟机4"); books.add("深入了解JVM虚拟机5"); for (String string : books) { System.out.println("foreach遍历集合元素:"+string); } } } package com.js.general; import java.util.Collection; import java.util.HashSet; import java.util.Iterator; /** * 使用Iterator来遍历集合元素 * @author jiangs * */ public class IteratorTest { public static void main(String[] args) { Collection<String> books = new HashSet<>(); books.add("深入了解JVM虚拟机1"); books.add("深入了解JVM虚拟机2"); books.add("深入了解JVM虚拟机3"); books.add("深入了解JVM虚拟机4"); books.add("深入了解JVM虚拟机5"); Iterator<String> iterator = books.iterator(); while(iterator.hasNext()) { System.out.println("iterator遍历集合元素:"+iterator.next()); } } } package com.js.general; import java.util.Collection; import java.util.HashSet; import java.util.Iterator; public class LambdaTest { public static void main(String[] args) { Collection<String> books = new HashSet<>(); books.add("深入了解JVM虚拟机1"); books.add("深入了解JVM虚拟机2"); books.add("深入了解JVM虚拟机3"); books.add("深入了解JVM虚拟机4"); books.add("深入了解JVM虚拟机5"); Iterator<String> iterator = books.iterator(); iterator.forEachRemaining(obj ->System.out.println("lambda遍历集合元素:"+obj)); } }
