用forEach替代for来循环
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* forEach 遍历collection容器
* @author 袁盛桐
*
*/
public class ForEachTest {
public static void main(String[] args) {
//forEach & List
List<String> items = new ArrayList<>();
items.add("a");
items.add("b");
items.add("c");
items.forEach(x->System.out.println(x));
//lamda函数增加函数
items.forEach(x->{if(x == "c") {System.out.println(x);}});
//forEach & Map
Map<String, Integer> items2 = new HashMap<>();
items2.put("a", 10);
items2.put("b", 20);
items2.put("c", 30);
items2.forEach((k,v)->System.out.println("Key: " + k + " Value: " + v));
//lamda函数增加函数
items2.forEach((k,v)->{
System.out.println("key: " + k + " value : " + v);
if("c".equals(k)){
System.out.println("This is c");
}
});
}
}