How do you convert a number to a string in javascript?

Examples

Convert a number to a string:

let num = 15;
let text = num.toString();

Try it Yourself »

Convert a number to a string, using base 2 (binary):

let num = 15;
let text = num.toString(2);

Try it Yourself »


Definition and Usage

The toString() returns a number as a string.


Note

Every JavaScript object has a toString() method.

The toString() method is used internally by JavaScript when an object needs to be displayed as a text (like in HTML), or when an object needs to be used as a string.

Normally, you will not use it in your own code.


Syntax

Parameters

Parameter Description
radix Optional.
The base to use.
Must be an integer between 2 and 36.
Base 2 is binary
Base 8 is octal
Base 16 is hexadecimal.

Return Value

Type Description
A string The number as a string.


More Examples

Convert a number to a string, using base 8 (Octal):

let num = 15;
let text = num.toString(8);

Try it Yourself »

Convert a number to a string, using base 16 (Hexadecimal):

let num = 15;
let text = num.toString(16);

Try it Yourself »


Browser Support

toString() is an ECMAScript1 (ES1) feature.

ES1 (JavaScript 1997) is fully supported in all browsers:

Chrome IE Edge Firefox Safari Opera
Yes Yes Yes Yes Yes Yes


The only valid solution for almost all possible existing and future cases (input is number, null, undefined, Symbol, anything else) is String(x). Do not use 3 ways for simple operation, basing on value type assumptions, like "here I convert definitely number to string and here definitely boolean to string".

Explanation:

String(x) handles nulls, undefined, Symbols, [anything] and calls .toString() for objects.

'' + x calls .valueOf() on x (casting to number), throws on Symbols, can provide implementation dependent results.

x.toString() throws on nulls and undefined.

Note: String(x) will still fail on prototype-less objects like Object.create(null).

If you don't like strings like 'Hello, undefined' or want to support prototype-less objects, use the following type conversion function:

/**
 * Safely casts any value to string. Null and undefined are converted to ''.
 * @param  {*} value
 * @return {string}
 */
function string (str) {
  return value == null ? '' : (typeof value === 'object' && !value.toString ? '[object]' : String(value));
}

The toString() method is a built-in method of the JavaScript Number object that allows you to convert any number type value into its string type representation.

How to Use the toString Method in JavaScript

To use the toString() method, you simply need to call the method on a number value. The following example shows how to convert the number value 24 into its string representation. Notice how the value of the str variable is enclosed in double quotation marks:

var num = 24;
var str = num.toString();

console.log(num); // 24
console.log(str); // "24"
Convert a number to string with toString() method

You can also call the toString() method immediately on a number value, but you need to add parentheses () to wrap the value or JavaScript will respond with an Invalid or unexpected token error.

The toString() method can also convert floating and negative numbers as shown below:

24.toString(); // Error: Invalid or unexpected token
(24).toString(); // "24"
(9.7).toString(); // "9.7"
(-20).toString(); // "-20"
Convert any type of numbers with toString() method

Finally, the toString() method also accepts the radix or base parameter. The radix allows you to convert a number from the decimal number system (base 10) to a string representing the number in other number systems.

Valid number systems for conversion include:

  • Binary system (base 2) that has 2 digits, 0 and 1
  • Ternary system (base 3) that has 3 digits 0, 1, and 2
  • Quaternary system (base 4) that has 4 digits, 0, 1, 2 and 3
  • And so on up to the Hexatridecimal system (base 36) that has the combination of Arabic numerals 0 to 9 and Latin letters A to Z
Number.toString(radix);
The syntax for toString() method, accepting radix parameter

The radix parameters accept a number type data with values ranging from 2 to 36. Here's an example of converting the decimal number 5 to its binary number (base 2) representation:

var str = (5).toString(2);

console.log(str); // "101"
Converting decimal number to binary number with toString() method

The decimal number 5 from the code above is converted to its binary number equivalent of 101 and then converted to a string.

How to Use Other Data Types with the toString() Method

Aside from converting the number type, the toString() method is also available for converting other data types into their string representations.

For example, you can convert an array type into its string representation as follows:

var arr = [ "Nathan", "Jack" ];
var str = arr.toString();

console.log(str); // "Nathan,Jack"
Convert an array to string with toString() method

Or a boolean type to string as shown below:

var bool = true;
var str = bool.toString();

console.log(str); // "true"

But I think you will most often use the toString() method to convert a number to a string instead of the others. That's what I usually do, too :)

Thanks for reading this tutorial

You may also be interested in other JavaScript tutorials that I've written, including Rounding Numbers with toFixed() Method and Calculating Absolute Value with Math.abs(). They are two of the most commonly asked JavaScript problems.

I also have a free newsletter about web development tutorials (mostly JavaScript-related).

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Can we convert number to string in JavaScript?

The toString() method is a built-in method of the JavaScript Number object that allows you to convert any number type value into its string type representation.

How are numbers converted to string in JavaScript?

The toString() method is used with a number num as shown in above syntax using the '. ' operator. This method will convert num to a string. Parameters Used: This method accepts a single optional parameter base.

How do you turn a number into a string?

There are several easy ways to convert a number to a string:.
int i; // Concatenate "i" with an empty string; conversion is handled for you. ... .
// The valueOf class method. ... .
int i; double d; String s3 = Integer.toString(i); String s4 = Double.toString(d);.

How do I convert a number to a string in TypeScript?

Use the String() object to convert a number to a string in TypeScript, e.g. const str = String(num) . When used as a function, the String object converts the passed in value to a primitive string and returns the result. Copied!