Mastering JavaScript Type Checking

Introduction

In this lab, we will explore the concept of type checking in JavaScript. Specifically, we will focus on the typeof operator and how it can be used to check whether a given value is a string primitive. Through a series of exercises and challenges, you will gain a deeper understanding of this fundamental aspect of JavaScript programming.

Skills Graph

%%%%{init: {'theme':'neutral'}}%%%% flowchart RL javascript(("`JavaScript`")) -.-> javascript/BasicConceptsGroup(["`Basic Concepts`"]) javascript/BasicConceptsGroup -.-> javascript/variables("`Variables`") javascript/BasicConceptsGroup -.-> javascript/data_types("`Data Types`") javascript/BasicConceptsGroup -.-> javascript/arith_ops("`Arithmetic Operators`") javascript/BasicConceptsGroup -.-> javascript/comp_ops("`Comparison Operators`") subgraph Lab Skills javascript/variables -.-> lab-28444{{"`Value Is String`"}} javascript/data_types -.-> lab-28444{{"`Value Is String`"}} javascript/arith_ops -.-> lab-28444{{"`Value Is String`"}} javascript/comp_ops -.-> lab-28444{{"`Value Is String`"}} end

Checking if a Value is a String

To check if a value is a string, use the typeof keyword followed by the value you want to check. This method only works for string primitives.

Here's an example code that checks if a given value is a string:

const isString = (val) => typeof val === "string";

You can use the isString function like this:

isString("10"); // true

Value Is String

Introduction

Skills Graph

Checking if a Value is a String

Summary

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