迭代器遍历集合

增强for循环遍历集合

Lambda表达式遍历集合

代码：

代码一：使用迭代器遍历集合

package com.itheima.day18_Collection;import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
// //使用迭代器遍历集合
public class CollectionTest1 {public static void main(String[] args) {Collection<String> c = new ArrayList<>();c.add("飞鸟马时");c.add("枣伊吕波");c.add("小鸟游星野");c.add("花子");System.out.println(c);//c = [飞鸟马时, 枣伊吕波, 小鸟游星野, 花子]//      it//使用迭代器遍历集合// 1、从集合对象中获取迭代器对象。Iterator<String> it = c.iterator();//我们应该使用循环结合迭代器遍历集合。while (it.hasNext()) {String str = it.next();System.out.println(str);}}
}

代码二：使用增强for遍历集合或者数组

package com.itheima.day18_Collection;import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
//  //使用增强for遍历集合或者数组。
public class CollectionTest2 {public static void main(String[] args) {Collection<String> c = new ArrayList<>();c.add("飞鸟马时");c.add("枣伊吕波");c.add("小鸟游星野");c.add("花子");System.out.println(c);//c = [飞鸟马时, 枣伊吕波, 小鸟游星野, 花子]//      ele//使用增强for遍历集合或者数组。//增强for快捷键：集合名或数组名.for()按回车for (String ele : c){System.out.println(ele);}//使用增强for遍历数组。String[] names = {"飞鸟马时","枣伊吕波","小鸟游星野","花子"};for (String name : names) {System.out.println(name);}}
}

代码三：结合Lambda表达式遍历集合

package com.itheima.day18_Collection;import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
//结合Lambda表达式遍历集合:
public class CollectionTest3 {public static void main(String[] args) {Collection<String> c = new ArrayList<>();c.add("飞鸟马时");c.add("枣伊吕波");c.add("小鸟游星野");c.add("花子");System.out.println(c);// default void forEach(Consumer<? super T>action): 结合Lambda表达式遍历集合:c.forEach(System.out::println);}
}

代码四：遍历集合中的自定义对象案例

案例分析：

Movie类：

package com.itheima.day18_Collection;public class Movie {private  String name;private double score;private String actor;@Overridepublic String toString() {return "Movie{" +"name='" + name + '\'' +", score=" + score +", actor='" + actor + '\'' +'}';}public Movie() {}public Movie(String name, double score, String actor) {this.name = name;this.score = score;this.actor = actor;}public String getName() {return name;}public void setName(String name) {this.name = name;}public double getScore() {return score;}public void setScore(double score) {this.score = score;}public String getActor() {return actor;}public void setActor(String actor) {this.actor = actor;}
}

CollectionTest4类（主程序）：

package com.itheima.day18_Collection;
/*目标:完成电影信息的展示。
new Movie("《肖生克的救赎》”，9.7，“罗宾斯”)
new Movie("《霸王别姬》"，9.6,"张国荣、张丰毅")
new Movie("《阿甘正传》"，9.5，"汤姆.汉克斯")
*/import java.util.ArrayList;
import java.util.Collection;public class CollectionTest4 {public static void main(String[] args) {//1、创建一个集合容器负责存储多部电影对象。Collection<Movie> movies = new ArrayList<>();movies.add(new Movie("《肖生克的救赎》",9.7,"罗宾斯"));movies.add(new Movie("《霸王别姬》",9.6,"张国荣、张丰毅"));movies.add(new Movie("《阿甘正传》",9.5,"汤姆.汉克斯"));System.out.println(movies.toString());for (Movie movie : movies) {System.out.println("电影名："+movie.getName());System.out.println("电影评分："+movie.getScore());System.out.println("电影主演："+movie.getActor());System.out.println("==========================================");}}
}