lambda表达式foreach如何获取遍历的index

[jim_long_]

public static void main(String args[]){
List<String> list = java.util.Arrays.asList("a","b","c");
list.forEach(s->{
//如何获取现在遍历到第几个了，如index
System.out.println(s);
});
}

[jim_long_]

自己先顶一下

[jim_long_]

要用lambda表达式实现

[vswen5]

for (int i = 0; i < list.size(); i++) { System.out.println(i); }

[梦里梦不出梦里梦的梦]

public static void main(String args[]){
List<String> list = java.util.Arrays.asList("a","b","c");
int id = 0;
list.forEach(s->{
//如何获取现在遍历到第几个了，如index
id = list.indexOf(s);
System.out.println(id);
System.out.println(s);
});
}

[二十六画生的博客]

引用 4 楼 qq_38455201 的回复:

public static void main(String args[]){
List<String> list = java.util.Arrays.asList("a","b","c");
int id = 0;
list.forEach(s->{
//如何获取现在遍历到第几个了，如index
id = list.indexOf(s);
System.out.println(id);
System.out.println(s);
});
}

如果有重复元素呢？

[wildyy]

lambda forEach是转换成iterator遍历的，你只能在外部自己定一个index，然后index++

[Braska]

List<String> list = java.util.Arrays.asList("a","b","c");
        Stream.iterate(0, i -> i + 1).limit(list.size()).forEach(i -> {
            System.out.println(String.valueOf(i) + list.get(i));
        });

[Anliexo]

Stream.iterate(0, i -> i + 1).limit(list.size()).forEach(i -> { System.out.println(i) }

[SqlsqLqS]

Local variable i defined in an enclosing scope must be final or effectively final

[SqlsqLqS]

引用 6 楼 wildyy 的回复:

lambda forEach是转换成iterator遍历的，你只能在外部自己定一个index，然后index++

Local variable i defined in an enclosing scope must be final or effectively final

[qq_22065839]

for((index, value) in list!!.withIndex()){ }

[薛之谦福州分谦]

加上steram一起用不香嘛 里面有过滤条件

[surging.dandelion]

少年，看这里：https://www.cnblogs.com/surging-dandelion/p/14662625.html