JS: How to remove white spaces only from inside of string

Question

I need in javascript language remove white spaces from inside of string, only. Left and right sides can have that spaces. I don't finding solution...

Maybe is some native function? Or sombedy have some regex?

I only have:

str = str.replace(/\s+/g, '');

But it removes white spaces from sides too.

I want:

var str = "   s dasd   asd sad sa d   ";
str = str.replace(/\s+/g, '');
// output
"   sdasdasdsadsad   ";

Answer 1

You may match and capture the leading/trailing whitespaces and restore in the result with the backreferences, and remove all other whitespaces.

var str = "   some text  ";
str = str.replace(/(^\s+|\s+$)|\s+/g, '$1');
console.log("'",str,"'");

Pattern details:

• (^\s+|\s+$) - Group 1 capturing one or more whitespaces 1) at the start of string (^\s+) or 2) at the end of the string (\s+$)
• | - or
• \s+ - 1+ whitespaces anywhere else in the string.

The $1 is the backreference to the capturing group contents that are inserted back into the resulting string.

To support   too, use alternation, (?:\s| ):

console.log("   s dasd   asd sad sa d   ".replace(/(^(?:\s| )+|(?:\s| )+$)|(?:\s| )+/g, '$1'));