Java String.split（）正则表达式 [英] Java String.split() Regex

问题描述

我有一个字符串：

String str = "a + b - c * d / e < f > g >= h <= i == j";

我想在所有运算符上拆分字符串，但在数组中包含运算符，所以结果数组如下所示：

I want to split the string on all of the operators, but include the operators in the array, so the resulting array looks like:

[a , +,  b , -,  c , *,  d , /,  e , <,  f , >,  g , >=,  h , <=,  i , ==,  j]

我目前有这个：

public static void main(String[] args) {
    String str = "a + b - c * d / e < f > g >= h <= i == j";
    String reg = "((?<=[<=|>=|==|\\+|\\*|\\-|<|>|/|=])|(?=[<=|>=|==|\\+|\\*|\\-|<|>|/|=]))";

    String[] res = str.split(reg);
    System.out.println(Arrays.toString(res));
}

这非常接近，它给出了：

This is pretty close, it gives:

[a , +,  b , -,  c , *,  d , /,  e , <,  f , >,  g , >, =,  h , <, =,  i , =, =,  j]

我能做些什么吗为了使多个字符操作符出现在数组中，就像我想要的那样？

Is there something I can do to this to make the multiple character operators appear in the array like I want them to?

作为次要问题并不是那么重要，有没有办法在正则表达式中修剪字母周围的空白？

And as a secondary question that isn't nearly as important, is there a way in the regex to trim the whitespace off from around the letters?

推荐答案

String[] ops = str.split("\\s*[a-zA-Z]+\\s*");
String[] notops = str.split("\\s*[^a-zA-Z]+\\s*");
String[] res = new String[ops.length+notops.length-1];
for(int i=0; i<res.length; i++) res[i] = i%2==0 ? notops[i/2] : ops[i/2+1];

这应该这样做。一切都很好地存储在 res 。

This should do it. Everything nicely stored in res.

这篇关于Java String.split（）正则表达式的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！