18 JavaScript Number Methods, Simplified examples
Introduction
The JavaScript number methods help you to work with numbers. JavaScript can work with various numeric values like integer, float, hexadecimal, decimal, exponential and octal values.
We will explain Javascript number methods in a simple manner with examples.

The toString() method.
This method converts the number into a string or returns a number as a string.
var x = 123; // x is number console.log(typeof(x)); //output: "number" var y = x.toString() // convert to string console.log(typeof(y)); //output: "string"
The toExponential() Method
Exponential notation is a method of writing numbers.
Exponential numbers take the form Xn, where X is multiplied by itself n times.
A simple example is 8 = 23 = 2×2×2.
In JavaScript toExponential() method returns a string with a rounded number written in exponential form.
var x = 323.34; var y = x.toExponential(); console.log(y); //output : 3.2334e+2
The toFixed() Method
The toFixed() method converts a given number into a string. It rounds to a specified number of decimals. Additional zeros are added to create the desired decimal length if the number of decimals is higher than the actual number.
var x = 323.3433; var y = x.toFixed(2); console.log(y); //same as //x.toFixed(0); // returns 4 //x.toFixed(2); // returns 3.66 //output: 323.34 //Example: if the given length in parameters is larger var x = 3.656; console.log(x.toFixed(4)); // output: 3.6560 console.log(x.toFixed(6)); //output: 3.656000
The toPrecision() Method
The toPrecision() method formats a number to a specified length with the given number of significant digits. It rounds the result where necessary. This method returns the value as a string.
Here is a simple example
var x = 7.938; x.toPrecision(); // output 7.938 x.toPrecision(2); // output 7.9 x.toPrecision(4); // output 7.938 x.toPrecision(6); // output 7.93800
The valueOf() Method
The valueOf() method returns the primitive value of a String object.
This method is called internally by JavaScript, and not explicitly in the code. All JavaScript data types have a valueOf() and a toString() method.
var x = 444; x.valueOf(); // output 444 from variable x
How to convert String variables to Numeric in JavaScript?
There are 3 JavaScript methods that can be used to convert string variables to numbers.
Number() method, parseInt() method and parseFloat() method
JavaScript global methods
The methods mentioned above are JavaScript global methods. this includes:
- Number() Method
- parseInt() method
- parseFloat() method
Number() Method
The Number() method is used to convert JavaScript variables to numbers.
consider the following example
// Example Number(true); // output: 1 Number(false); // output: 0 Number("20"); // output: 20 Number(" 20 "); // output: 20 Number("20.43"); // output: 20.43 Number("20,33"); // output: NaN (Not a Number) Number("20 33"); // output: NaN Number("John Doe"); // output: NaN //
The Number() method is also useful to convert Dates to numbers. It returns the number of milliseconds since 1-1-1970.
// Example let dateToNumber = Number(new Date("2021-01-01")); console.log(dateToNumber); // output: 1609459200000 //
parseInt() method
parseInt() parses a string and returns a whole number. Use spaces as parameters but it returns only the first number.
This method returns NaN ( not a number ) if the given string is impossible to convert to a number.
// Example parseInt("20"); // output: 20 parseInt("20.73"); //output: 20 parseInt("20 70"); // output: 20 parseInt("20 Days"); // output: 20 parseInt("Date 20"); // output: NaN //
parseFloat() Method
The parseFloat() Method in JavaScript parses a string and returns a floating-point number. It also returns NaN if the given string is impossible to convert to a string.
// Example parseFloat("20"); // output: 20 parseFloat("20.71"); // output: 20.71 parseFloat("20 10"); // output: 20 parseFloat("20 Days"); // output: 20 parseFloat("Number 20"); // output: NaN //
Conclusion on JavaScript Number Methods
The above topic covers all the fundamental topics about JS methods and functions of Numbers
You can represent numeric dates by the Number object, which can be either integers or floating-point numbers.
The Number object in JavaScript is a wrapper for primitive numeric values.
There is only one kind of number data type in JavaScript, and it does not differentiate between integers and floating-point values.