Alert an array string with .replace

Question

Why if i print an array (converted to a string) the .replace function works only on the first ,?

var messages = ["a", "b", "c"];

alert(messages.toString().replace(',',''));

Answer 1

That is how .replace() works, it only replaces the first match.

To replace all matches, simply use regex

.replace(/,/g, '') the g means global, and tells replace to look for ALL matches. The / are regex syntax. Learn more here https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions

Answer 2

If you want to replace all the occurance, you have to use the global replace

/,/g 

So

alert(messages.toString().replace( /,/g,''));

https://jsfiddle.net/mn93pxth/1/

Answer 3

Because that's what passing a string to replace does. Using a regular expression with the global g flag solves it.

var messages = ["a", "b", "c"];

alert(messages.toString().replace(/,+/g,''));