Java正则表达式特殊字符

Question

I want to replace xx* with x .

I tried string.replaceAll("xx*", "x");

but in regex * is special so I need to give a \\* but to give a \\ in java i need to give \\\\

==> finally it should work with string.replaceAll("xx\\\\*", "x");

but when the string contains xx* the above statement fails in replacing xx* with x

Answer 1

1. You have to reassign the result of the replaceAll() call to the string variable - that method returns a new string as opposed to modifying the string you call it on.

2. Don't use replaceAll() !! Use replace() when dealing with literal strings:

    string = string.replace("xx*", "x"); 

Answer 2

Strings are immutable. Assign the result of replaceAll to the original value

string = string.replaceAll("xx\\*", "x");

Answer 3

string.replaceAll("xx\\\\*", "x") will not change the given string, as strings are immutable in Java. You need to use the returned value, for instance by assigning it back to the original variable: string = string.replaceAll("xx\\\\*", "x")

Answer 4

Use string.replaceAll("xx\\\\*", "x"); instead of string.replaceAll("xx\\*", "x");

This is working fine.

Live Demo here .