Add Interpolate A String Into A Regex as a javascript til

README.md

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+- [Interpolate A String Into A Regex](javascript/interpolate-a-string-into-a-regex.md)
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javascript/interpolate-a-string-into-a-regex.md

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+# 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:
+
+```javascript
+const myRegex = /^Some Customizable Text$/;
+```
+
+This works great for fixed strings, but won't cut it if you need to work
+_variable_ strings.
+
+What's needed to work with variables is the
+[`RegExp`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp)
+constructor:
+
+```javascript
+const customizableString = "Some Customizable Text";
+const myRegex = new RegExp(`^${customizableString}$`);
+```
+
+You can build up some string with string variables and regex syntax and `new
+RegExp()` will turn it into a regex.
+
+[source](https://makandracards.com/makandra/15879-javascript-how-to-generate-a-regular-expression-from-a-string)