What will be the best regex Expression for censoring email?

Question

Hello I am stuck on a problem for censoring email in a specific format, but I am not getting how to do that, please help me!

Email : [email protected]

Required : e***********@e******.com

Help me getting this in javascript, Current code I am using to censor :

const email = [email protected];
const regex = /(?<!^).(?!$)/g;
const censoredEmail = email.replace(regex, '*');

Output: e**********************m

Please help me getting e***********@e******.com

Answer 1

If there should be a single @ present in the string, you can capture all the parts of the string and do the replacement on the specific groups.

• ^ Start of string
• ([^\s@]) Capture the first char other than a whitespace char or @ that should be unmodified
• ([^\s@]*) Capture optional repetitions of the same
• @ Match literally
• ([^\s@]) Capture the first char other than a whitespace char or @ after it that should be unmodified
• ([^\s@]*) Capture optional repetitions of the same
• (\.[^\s.@]+) Capture a dot and 1+ other chars than a dot, @ or whitespace char that should be unmodified
• $ End of string

Regex demo

In the replacement use all 5 capture groups, where you replace group 2 and 4 with *.

const regex = /^([^\s@])([^\s@]*)@([^\s@])([^\s@]*)(\.[^\s.@]+)$/;
[
  "[email protected]",
  "test"
].forEach(email =>
  console.log(
    email.replace(regex, (_, g1, g2, g3, g4, g5) =>
      `${g1}${"*".repeat(g2.length)}@${g3}${"*".repeat(g4.length)}${g5}`)
  )
);