CODEWITHSUNDEEP
javascriptregexstring
Arian
Arian

Reputation: 7719

Replace all characters including whitespace in Javascript

I have the following string , s1 , as a part of a longer text (which doesn't have the following patter in it i.e. this pattern only happens once through out the text. The text also includes white spaces and new lines)

<!-- COMPONENTS_LIST_START -->
* [line-vis](line-chart)
* [trend-vis](trend-vis)
<!-- COMPONENTS_LIST_END -->

I want to replace it with the following string , s2 : 

<!-- COMPONENTS_LIST_START -->
* [line-vis](line-chart)
* [trend-vis](trend-vis)
* [common-vis](common-vis)
<!-- COMPONENTS_LIST_END -->

I use the following RegEx but it doesn't match it : 

str1.replace(/<!-- COMPONENTS_LIST_START -->(\s|.)*<!-- COMPONENTS_LIST_END -->/, str2)

Doesn't this : (\s|.)* mean , all characters including white space characters ?

Upvotes: 0

Views: 65

Answers (2)

Trott
Trott

Reputation: 70055

Your regular expression works. The problem you are experiencing is that .replace() does not mutate the string. It returns a new string. If you want it to mutate the string, you need to assign the return value.

str1 = str1.replace(/<!-- COMPONENTS_LIST_START -->(\s|.)*<!-- COMPONENTS_LIST_END -->/, str2);

Upvotes: 2

Federico Piazza
Federico Piazza

Reputation: 30985

You are using a greedy regex so you will mess things. Btw, you can use [\S\s] ungreedy instead like this:

str1.replace(/<!-- COMPONENTS_LIST_START -->[\S\s]*?<!-- COMPONENTS_LIST_END -->/, str2)

The idea behind [\S\s]*? is to match everything until the first occurrence of your pattern, in your case <!-- COMPONENTS_LIST_END -->

And also as Trott pointed in his answer, assign the string a result:

str1 = str1.replace(/<!-- COMPONENTS_LIST_START -->[\S\s]*?<!-- COMPONENTS_LIST_END -->/, str2);

Upvotes: 2

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