JavaScript Check if String as Variable

Home /

Table of Contents

Brief about ‘String’ in Javascript

In programming, a string is a sequence of characters. It is used to represent text in a program. Strings are commonly used to store names, addresses, sentences, and other forms of text. They are used in many programming languages, including JavaScript.

JavaScript strings are enclosed in single or double quotes, for example:



Strings are also commonly used in JavaScript for handling and parsing text data, such as when displaying text on a webpage, or when handling data from a server.

Typeof’ operator

The ‘typeof’ operator in JavaScript is used to determine the type of a variable or expression. It returns a string indicating the type of the operand.

The ‘typeof’ operator can be used to check the type of a variable, such as whether it is a string, number, boolean, or object. It can also be used to check if a variable has been defined or not, it will return ‘undefined’ if the variable is not defined.

It’s important to note that ‘ typeof ‘ returns ‘ ‘object‘ ‘ for objects, arrays and functions, and it returns ‘ ‘undefined’ ‘ if the variable is undefined. ’ ‘undefined’ ‘ is not a keyword like null and NaN. Also, typeof returns ‘ ‘object’ ‘ for null, so it’s not the best way to check for it.You can use ‘typeof’ to check the type of a variable before using it in a program, to ensure that the variable has the expected type and to handle any type mismatches appropriately.

Determine if a ‘variable’ is a ‘string’ or something else in JavaScript

In JavaScript, you can use the typeof operator to determine the type of a variable.

For example, to determine if a variable is a string, you can use the following code:

if (typeof variable === 'string') {
    // variable is a string
} else {
    // variable is not a string

You can also use the ‘instanceof’ operator to check if an object is an instance of a constructor, such as ‘String’

Convert Integer Type to String

In JavaScript, you can convert an integer to a string using the ‘toString()‘ method, which is available on all numbers. Here’s an example:

const number = 42;
const string = number.toString();
console.log(string); // Output: "42"

In this example, we define an integer variable ‘number‘ with a value of ‘42.’ We then call the toString() method on ‘number‘ to convert it to a string, and assign the result to a new variable ‘string‘. Finally, we log ‘string‘ to the console, which outputs the string "42".

You can also use the ‘String()‘ constructor function to convert a number to a string, like this:

const number = 42;
const string = String(number);
console.log(string); // Output: "42"

This code is functionally equivalent to the previous example, but uses the ‘String()‘ constructor function instead of the ‘toString()‘ method.

Share The Tutorial With Your Friends

Check Our Ebook for This Online Course

Advanced topics are covered in this ebook with many practical examples.

Other Recommended Article