How to check if a variable is a string in JavaScript

To check that a JS variable is of a type string, you can use 2 operators: instanceof and typeof. Here’s a quick solution.

if (typeof text === 'string' || text instanceof String) {
  // it's a string!
} else {
  // it's not a string :(
}

Using only typeof won’t work in a scenario when the string was created as an object using the new String() syntax.

const s = new String('javascript string object');

console.log(typeof s); // object

So, if you’re looking to check for both primitive strings and string objects, it’s best to use the check that combines both typeof and instanceof.