list.forEach uses return to jump out of this loop (the function is similar to the continue of a for loop), and there is no jump out of the loop function (that is, no break function of the for loop)
Source code
package com.me.address;
import java.util.Arrays;
import java.util.List;
/**
* @author yanyg
* @since 2020/9/1
*/
public class ListforEachTest {
private static final String DEFAULT_STR = "7777";
public static void main(String[] args) {
List<String> list = Arrays.asList("6666", "7777", "8888", "9999");
list.forEach(t -> {
if (t.equals(DEFAULT_STR)) {
// 跳槽本次循环，继续下一次循环，类似 continue
return;
}
System.out.println(t);
});
System.out.println("=====================================");
for (String t : list) {
if (t.equals(DEFAULT_STR)) {
// 跳槽本次循环，继续下一次循环
continue;
}
System.out.println(t);
}
System.out.println("=====================================");
for (String t : list) {
if (t.equals(DEFAULT_STR)) {
// 跳出循环
break;
}
System.out.println(t);
}
}
}
operation result
6666
8888
9999
=====================================
6666
8888
9999
=====================================
6666
stream().anyMatch
- Code
public static void main(String[] args) {
List<String> list = Arrays.asList("6666", "7777", "8888", "9999");
/**
* 每次都执行一次，flag 是最后一次匹配的值
* 可以设置变量存储想要的 true 或 false
*/
boolean flag = list.stream().anyMatch(t -> {
System.out.println("================");
if ("777".equals(t)) {
return true;
} else {
return false;
}
});
System.out.println("flag=" + flag);
System.out.println("+++++++++++++++++++++++++");
List<String> strs = Arrays.asList("a", "a", "a", "a", "b");
// 判断的条件里，任意一个元素成功，返回true
boolean aa = strs.stream().anyMatch(str -> str.equals("a"));
System.out.println("aa=" + aa);
}
- result
================
================
================
================
flag=false
+++++++++++++++++++++++++
aa=true