How to check if typeof is a string in JavaScript?

Table of Contents

• Introduction
• Checking if typeof is a String in JavaScript
  • Example 1: Checking a String with typeof
  • Example 2: Checking a Non-String Value
• Practical Use Case: Validating User Input
• Conclusion

Introduction

In JavaScript, it’s common to check if a variable is a string before performing operations specific to strings. The typeof operator is a simple and effective way to determine the type of a variable. When applied to a string, it returns "string". This guide explains how to check if a variable is a string using typeof.

Checking if typeof is a String in JavaScript

To check if a variable is a string in JavaScript, you use the typeof operator and compare its result to "string". If typeof returns "string", then the variable is indeed a string.

Example 1: Checking a String with typeof

In this example, the typeof operator returns "string" for the myVariable, so the condition evaluates to true.

Example 2: Checking a Non-String Value

Here, the variable holds a number, so typeof returns "number", and the condition evaluates to false.

Practical Use Case: Validating User Input

You can use the typeof check to validate user input when expecting a string.

This ensures that only string inputs are processed, avoiding errors that could occur when handling non-string data.

Conclusion

To check if a variable is a string in JavaScript, the typeof operator is your best tool. By comparing typeof variable === "string", you can confidently determine if a variable holds a string and handle it accordingly. This approach is simple, effective, and commonly used in JavaScript development.