正则表达式拆分与分隔符同时保持分隔符

Question

我正在尝试将带分隔符的字符串拆分为数组，同时保留分隔符。

我拥有的字符串是：“2 + 37/4 + 26”。

我希望数组为：[2,+,37,/,4,+,26]

Answer 1

您可以使用lookarounds进行拆分：

String[] tok = input.split("(?<=[+*/-])|(?=[+*/-])");

RegEx Demo

<强>解释

(?<=[+*/-])  # when preceding character is one of 4 arithmetic operators
|            # regex alternation
(?=[+*/-])   # when following character is one of 4 arithmetic operators