Question

This almost has the answer…
How do you use a variable in a regular expression?

I need to know if I can use variables instead of hardcode in the regex?

str1 = str1.replace(/abcdef/g, "stuvwxyz");

can I use variables instead of /abcdef/g and “stuvwxyz”

Answer 1

Of course that you can, every single bit of this can be dynamic:

var pattern = 'abcdef';
var input = 'stuvwxyz';
var modifiers = 'g';
var regex = new RegExp(pattern, modifiers);
var str1 = 'Hello abcdef';
str1 = str1.replace(regex, input);

Checkout the docs as well.