Javascript: what is white space in regex?

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What is white space in js regex?
I am trying to find whitespace using the lastindexof function, but it doesn't work.

What I have tried:

JavaScript

var str = "Happy New Years";
var p = str.lastIndexOf(" ");
console.log(p);   // return 9
var p = str.lastIndexOf("/ /gi");
console.log(p);   // return -1
var p = str.lastIndexOf("/\s/gi");
console.log(p);   // return -1

Posted 1-Jan-23 8:36am

Chopin2001

Updated 2-Jan-23 3:29am

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2 solutions

Solution 2

lastIndexOf does not support a regex pattern. See here: String.prototype.lastIndexOf() - JavaScript | MDN[^]

Posted 2-Jan-23 3:29am

0x01AA

Comments

Chopin2001 2-Jan-23 11:46am

Wow. I didn't know that. Thanks a lot.

0x01AA 2-Jan-23 11:53am

You are welcome.
You can use a 'workaround', have a look here: RegExp: lastIndex - JavaScript | MDN[^]

Little bit tricky with a loop, but working ;)

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OriginalGriff · Accepted Answer · 2023-01-01T09:06:00

Solution 1

Whitespace in a regex is "\s".
If you are going to use regular expressions, get a copy of Expresso[^] - it's free, and it examines, tests, and generates Regular expressions.

Posted 1-Jan-23 9:06am

OriginalGriff

Comments

Chopin2001 1-Jan-23 15:42pm

Thanks a lot.
I don't know why it's doesn't work.