Javascript: Check string to be the pattern of RegExp Object

Question

I need to find a solution for checking a string that can be the pattern of RegExp Object like this. str => new RegExp( str ) can run and return a regex to use with test(), match(), ...

How can I check str available to use like the above way? (I am trying to create a component like the website regex101.com so I want to know how they can check and show errors in regular expression input) Thank you a lot.

Answer 1

Just use a try catch to test it:

function isValidRegex(str) {
  try {
    new RegExp(str);
    return true;
  } catch(ex) {
    return false;
  }
}