用于String中多个匹配的Java indexOf方法 [英] Java indexOf method for multiple matches in String

问题描述

我对indexOf方法有疑问。我想在字符串中找到多个X的情况。

I had a question about the indexOf method. I want to find multiple cases of "X" in a string.

假设我的字符串是x是x是x是x，我想在所有中找到x它的指数位置。
但是你如何针对多种情况这样做呢？这甚至可以用indexOf吗？

Suppose my string is "x is x is x is x", I want to find x in all of its index positions. But how do you do this for multiple cases? Is this even possible with indexOf?

我做了int temp = str.indexOf（'x'）;
找到第一个x。我试着做一个for循环，其中我被初始化为字符串的长度，这不起作用，因为我一直在找到第一个x。

I did int temp = str.indexOf('x'); It find the first x. I tried to do a for loop where i is initialized to length of string and this did not work since I kept finding the first x over and over.

for (int y = temp1; y >= 0;y-- ) 
{
    int temp = str.indexOf('x');
    System.out.println(temp);
}

但这不起作用。我应该使用正则表达式吗？因为我真的不知道如何使用正则表达式方法。

But this does not work. Am I supposed to use regex? Because I don't really know how to use regex method.

任何帮助都将不胜感激，谢谢！

Any help would be appreciated, thanks!

推荐答案

indexOf 方法的第二个变体，它将start-index作为参数。

There is a second variant of the indexOf method, which takes a start-index as a parameter.

i = str.indexOf('x');
while(i >= 0) {
     System.out.println(i);
     i = str.indexOf('x', i+1);
}

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