Java8 forEach方法

1 Java8 forEach方法的介绍

Java提供了一个新的forEach() 方法来迭代元素。它在Iterable和Stream接口中定义。这是Iterable接口中定义的默认方法。扩展Iterable接口的集合类可以使用forEach循环来迭代元素。

此方法采用单个参数，该参数是功能接口。因此，您可以将lambda表达式作为参数传递。

2 Java8 forEach方法的声明

default void forEach(Consumer<super T>action)  

3 Java8 forEach方法的案例1

/**
 * https://www.jhelp.com
 */
import java.util.ArrayList;  
import java.util.List;  
public class ForEachExample {  
    public static void main(String[] args) {  
        List<String> gamesList = new ArrayList<String>();  
        gamesList.add("Football");  
        gamesList.add("Cricket");  
        gamesList.add("Chess");  
        gamesList.add("Hocky");  
        System.out.println("------------Iterating by passing lambda expression--------------");  
        gamesList.forEach(games -> System.out.println(games));  
          
    }  
}  

输出结果为：

------------Iterating by passing lambda expression--------------
Football
Cricket
Chess
Hocky

4 Java8 forEach方法的案例2

/**
 * https://www.jhelp.com
 */
import java.util.ArrayList;  
import java.util.List;  
public class ForEachExample {  
    public static void main(String[] args) {  
        List<String> gamesList = new ArrayList<String>();  
        gamesList.add("Football");  
        gamesList.add("Cricket");  
        gamesList.add("Chess");  
        gamesList.add("Hocky");  
        System.out.println("------------Iterating by passing method reference---------------");  
        gamesList.forEach(System.out::println);  
    }  
}  

输出结果为：

------------Iterating by passing method reference---------------
Football
Cricket
Chess
Hocky