Format phone number in Javascript-CodePudding

I need to format phone number for example by replace():

From: 48 XX XXX XX XX where X is a number.

Example: 48 12 345 67 89

To: 48 XXX XXX XXX

Example: 48 123 456 789

Edit:

My work:

First, I tried to remove the spaces in string: phone.replace(' ', '');:

Before: 48 12 312 31 23

After: 4812 312 31 23

Conclusion: Something is wrong because it only formatted the first space instead of everything.

I also tried to separate it into parts, based on other questions about regex:

phone.replace(/(\d{3})(\d{3})(\d{3})(\d{3})/gi, '$1 $2 $3 $4'); and

phone.replace(/(\d{3})" "(\d{3})" "(\d{3})" "(\d{3})/gi, '$1 $2 $3 $4');

and many other configurations like this.

Before: 48 12 312 31 23

After: 48 12 312 31 23

Conclusion: For sure, something is wrong, there is no change. The problem is with the regex.

CodePudding user response：

You could use a regex replacement approach here:

var input = " 48 12 345 67 89";
var output = input.replace(/\s /g, "")
                  .replace(/^(\ \d{2})(\d{3})(\d{3})(\d{3})$/, "$1 $2 $3 $4");
console.log(input   " => "   output);