JavaScript 正则表达式替换整个单词

Question

I have a variable:

var str = "@devtest11 @devtest1";

I use this way to replace @devtest1 with another string:

str.replace(new RegExp('@devtest1', 'g'), "aaaa")

However, its result ( aaaa1 aaaa ) is not what I expect. The expected result is: @devtest11 aaaa . I just want to replace the whole word @devtest1 .

How can I do that?

Answer 1

Use the \\b zero-width word-boundary assertion.

var str = "@devtest11 @devtest1";
str.replace(/@devtest1\b/g, "aaaa");
// => @devtest11 aaaa

If you need to also prevent matching the cases like hello@devtest1 , you can do this:

var str = "@devtest1 @devtest11 @devtest1 hello@devtest1";
str.replace(/( |^)@devtest1\b/g, "$1aaaa");
// => @devtest11 aaaa

Answer 2

Use word boundary \\b for limiting the search to words.

Because @ is special character, you need to match it outside of the word.

\\b assert position at a word boundary (^\\w|\\w$|\\W\\w|\\w\\W) , since \\b does not include special characters.

 var str = "@devtest11 @devtest1"; str = str.replace(/@devtest1\\b/g, "aaaa"); document.write(str);

If your string always starts with @ and you don't want other characters to match

 var str = "@devtest11 @devtest1"; str = str.replace(/(\\s*)@devtest1\\b/g, "$1aaaa"); // ^^^^^ ^^ document.write(str);

Answer 3

如果单词被非空格字符包围， \\b将无法正常工作..我建议使用以下方法

var output=str.replace('(\s|^)@devtest1(?=\s|$)','$1aaaa');