Javascript Regex for data masking

Question

I've been trying to figure out how to specifically mask certain parts of the string.

For example, if I were to mask first four letters in an email:

[email protected] => ****[email protected]

and

mask four numbers before the last four numbers of a phone number:

+15123452345 => +151****2345

What would each of these regex expressions be using replace?

Sweeper · Accepted Answer · 2017-12-28 03:38:22Z

1

For the first one, just match the start of the string and 4 more .:

^.{4}

For the second one, use this:

.{4}(?=.{4}$)

This matches 4 . until it sees that after it, there are 4 more . followed by the end of string.

answered Dec 28, 2017 at 3:38

Sweeper

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2 Comments

Can you tell how can replace all matching with X

You should do some research about the regex API of your language first. @Anuragpareek it will tell you how to do replacements.