How to check if a variable is a string in JavaScript

To check if a variable is a string in JavaScript, use the typeof operator, e.g. typeof a === 'string'. If the typeof operator returns "string", then the variable is a string. For all other values, the variable is not a string.

let name = 'Atta'

if (typeof name === 'string') {
  console.log(`Variable is a string`)
} else {
  console.log(`Variable is NOT a string`)
}

// Output => Variable is a string

In the above example, we used the typeof operator to check if a variable is a string.

The typeof operator returns a string indicating the type of the given value. Here are a few more examples:

console.log(typeof 'john')          // "string"
console.log(typeof '4')             // "string"
console.log(typeof true)            // "boolean"
console.log(typeof [])              // "object"
console.log(typeof {})              // "object"
console.log(typeof 5)               // "number"
console.log(typeof null)            // "object"
console.log(typeof (() => {}))      // "function"

Unlike the other operators, the typeof operator does not throw a ReferenceError exception when used with a variable that is not declared:

if (typeof price === 'string') {
  console.log(`Variable is a string`)
} else {
  console.log(`Variable is NOT a string`)
}

// Output => Variable is NOT a string

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