Remove all non-alphanumeric Characters from String in JS

Remove all non-alphanumeric Characters from String #

To remove all non-alphanumeric characters from a string, call the replace() method, passing it a regular expression that matches all non-alphanumeric characters as the first parameter and an empty string as the second. The replace method returns a new string with all matches replaced.

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const str = 'A!@#b$%^c&*(';

const replaced = str.replace(/[^a-z0-9]/gi, '');
console.log(replaced); // 👉️ Abc

We passed the following parameters to the String.replace method:

1. a regular expression that we want to match in the string.
2. the replacement for each match. For our purposes, an empty string because we want to remove all non-alphanumeric characters.

The forward slashes / / mark the beginning and end of the regular expression.

The square brackets [] are called a character class.

The caret ^ symbol means "NOT the following". In our case, this means not any letters in the range of a-z and not any numbers in the range of 0-9.

The i flag makes our match case-insensitive by targeting all uppercase and lowercase characters.

If you ever need help reading a regular expression, check out this regex cheatsheet by MDN.

If your use case requires you to also preserve spaces, hyphens or other characters, add them between the square brackets [].

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const str = 'A!@# b$% ^c&-*(';

const replaced = str.replace(/[^a-z0-9 -]/gi, '');
console.log(replaced); // 👉️ A b c-

The code snippet preserves all alphanumeric characters, spaces and hyphens. You could adjust the regex to your needs by adding or removing characters between the square brackets [].

Further Reading #

• Check if String contains only Digits in JavaScript
• Check if String contains only Letters and Numbers in JS