为什么此 Java String.replaceAll() 代码不起作用? [英] Why does this Java String.replaceAll() code not work?

问题描述

我之前在 Java 中使用过 string.replaceAll() 并没有遇到任何问题，但我对这个感到困惑.我认为它只会起作用，因为没有/"或$"字符.这是我想要做的:

I have used string.replaceAll() in Java before with no trouble, but I am stumped on this one. I thought it would simply just work since there are no "/" or "$" characters. Here is what I am trying to do:

String testString = "__constant float* windowArray";
String result = testString.replaceAll("__constant float* windowArray", "__global float* windowArray");

变量结果最终看起来与 testString 相同.我不明白为什么没有变化，请帮忙.

The variable result ends up looking the same as testString. I don't understand why there is no change, please help.

推荐答案

传递给 replaceAll 的第一个参数仍被视为正则表达式.* 字符是一个特殊字符的含义，粗略地说，字符串中的前一个东西(这里:t)，可以出现0次或多次.您想要做的是为正则表达式转义 * .您的第一个参数应该看起来更像:

The first argument passed to replaceAll is still treated as a regular expression. The * character is a special character meaning, roughly, the previous thing in the string (here: t), can be there 0 or more times. What you want to do is escape the * for the regular expression. Your first argument should look more like:

"__constant float\\* windowArray"

第二个参数，至少就您的目的而言，仍然只是一个普通字符串，因此您无需在那里转义 *.

The second argument is, at least for your purposes, still just a normal string, so you don't need to escape the * there.

String result = testString.replaceAll("__constant float\\* windowArray", "__global float* windowArray");

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