I am using regex in javascript and want to replace all the digits in a number except the last four with '#'. I have figured out how to replace all the digits with '#', what do I do to not replace the last four? Here is my code so far. return cc.replace(/[0-9]/g, "#")

I am using regex in javascript and want to replace all the digits in a number except the last four with '#'. I have figured out how to replace all the digits with '#', what do I do to not replace the last four? Here is my code so far. return cc.replace(/[0-9]/g, "#")

• javascript
• regex

• Is the string of a specific size? – acupofjose Commented Feb 19, 2016 at 16:24
• 2 What if there are less than 4 digits? – Oriol Commented Feb 19, 2016 at 16:26

1 Answer 1

use this pattern

\d(?=\d{4})

and replace with #
Demo