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I want to add variables in regex, so i can update the regex frequently in function call depending on the parameters.

What I have tried:

JavaScript
let regex = '/year B.Tech sem Sem/g';
let year = 'II';
let sem = 'I';
regex = regex.replace('year',year);
regex = regex.replace('sem',sem);
console.log(regex)
// here the output is = /II B.Tech I Sem/g
regex = new RegExp(regex);
console.log(regex)
// here the regex changes and the output = /\/II B.Tech I Sem\/g/
Posted
Updated 10-Mar-21 3:51am
v2
Comments
NotTodayYo 9-Mar-21 14:22pm    
OK, where are you stuck?

You're already using variables.

1 solution

Simple:
JavaScript
let year = 'II';
let sem = 'I';
let regex = new RegExp(`${year} B.Tech ${sem} Sem`, "g");
You need to pass the options to the RegExp constructor, and remove the regex literal delimiters from your string.

RegExp - JavaScript | MDN[^]
Template literals (Template strings) - JavaScript | MDN[^]
 
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