interpolate-a-string-into-a-regex.md

Interpolate A String Into A Regex

You can build up strings with concatenation or the template literal syntax. If you're incorporating variables as part of this string building, that's called interpolation.

But what if you need to interpolate variables into a regular expression (regex)?

A regex literal looks like this:

const myRegex = /^Some Customizable Text$/;

This works great for fixed strings, but won't cut it if you need to work variable strings.

What's needed to work with variables is the RegExp constructor:

const customizableString = "Some Customizable Text";
const myRegex = new RegExp(`^${customizableString}$`);

You can build up some string with string variables and regex syntax and new RegExp() will turn it into a regex.

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