javascript replace() is not replacing all the characters match

Question

I want to turn /Admin/ListOfMovies into _Admin_ListOfMovies using replace().

var $id = id.replace('/', '_');

It looks like it only replacing the first /. How do I replace all of them?

Thanks for helping.

possible duplicate of [Javascript multiple replace](http://stackoverflow.com/questions/832257/javascript-multiple-replace) — , Aug 07 '13 at 01:01
I repeatedly found that the default behavior of "replace" is almost useless and dangerous. Why would I want to replace the first occurrence only (in a general case) ? why not the second or third or last ? this method is a major bug creator because of it's very unexpected behavior. I would recommend creating a method with another name in String.prototype that uses the regex version suggested by Matt and start using it everywhere in your team. — Cesar, Jan 30 '19 at 09:07

score 27 · Accepted Answer · answered Aug 07 '13 at 01:00

27

Use a regex with the g flag.

var $id = id.replace(/\//g, '_');

answered Aug 07 '13 at 01:00

Matt Ball

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dash killer --> stringWithDashes.replace(/-/g, ''); – beauXjames Mar 29 '17 at 19:36
@beauXjames I'm not sure I understand what you're getting at. Do you mind elaborating? – Matt Ball Mar 29 '17 at 20:36
1

just sharing the reason d'etre for me even being here...I had to kill some dashes and your answer helped...was just showing how it worked with dashes. – beauXjames Mar 31 '17 at 15:28

score 10 · Answer 2 · answered Aug 07 '13 at 01:00

10

I hate javascript replace since it always wants a regex. Try this

var $id=id.split("/").join("_");

answered Aug 07 '13 at 01:00

chiliNUT

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Both from a performance and clarity-of-intent perspective, I cannot see how this is ever preferable. – Matt Ball Aug 07 '13 at 01:04
1

@MattBall maybe when you have a dynamic separator and don't feel like escaping it to construct a RegExp object? – Fabrício Matté Aug 07 '13 at 01:07
3

@MattBall In most languages, using replace lets you replace a string with a string, instead of needing a regex every time. the subject.split(search).join(replacement) construct is the closest thing in JS to a normal string replace. It is absurd that you should be required to use a regex everytime you want to do string replacement in JS. – chiliNUT Aug 07 '13 at 01:09

score 2 · Answer 3 · answered Aug 07 '13 at 01:19

If you don't want to use the global flag which will do the replace function twice on your string, you can do this method which is a bit more specific and only replaces it once; it's also useful to know for other situations.

var $id = id.replace(/\/(\w+)\/(\w+)/, '_$1_$2');

score 0 · Answer 4 · answered Aug 07 '13 at 01:56

function strReplace( str ) {
if( typeof str === 'string' ) {
    return text.replace( /[\/]/g, function( match, pos, originalText ) {
        if( match === '/' ){
            return '_';
        }
    });
}
return '';
}

console.log( strReplace( /Admin/ListOfMovies ) );

javascript replace() is not replacing all the characters match

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