How to Escape Regular Expression Special Characters in JavaScript

Escaping regular expression special characters is crucial for achieving precision in pattern matching. To do this in JavaScript, you can utilize the \ character to prefix characters that hold special meaning within regular expressions.

For instance, if you want to match a literal [, you would need to escape it as \[. However, to automate this process, it's convenient to employ a function.

function escapeRegExp(text) {
  return text.replace(/[-[\]{}()* ?.,\\^$|#\s]/g, '\\$&');
}

In this function, the replace method identifies and replaces special characters with their escaped counterparts. The updated version of the character is prefixed with a \, ensuring that the regular expression engine treats it as a literal character rather than a special token.

To illustrate the application of this function, consider the following code:

const escapedString = escapeRegExp("[Munees]waran");

The escapedString now holds the value \[Munees\]waran, where the brackets [ and ] are escaped to prevent the regular expression engine from interpreting them as range delimiters.

Originally, a more specific function named RegExp.escape was available, but due to its limited escape capabilities, it has been deprecated. Instead, for comprehensive regular expression escaping, it's recommended to utilize the escapeRegExp function mentioned above.