How to get decimal portion of a number using JavaScript ?

Given a float number, The task is to separate the number into integer and decimal parts using JavaScript. For example, a value of 15.6 would be split into two numbers, i.e. 15 and 0.6 Here are a few methods discussed. 

These are the following methods:

Javascript String split() Method

This method is used to split a string into an array of substrings and returns the new array. 

Syntax:

string.split(separator, limit);

Parameters:

• separator: This parameter is optional. It specifies the character, or the regular expression, to use for splitting the string. If not used, the whole string will be returned (an array with only one item) 
• limit: This parameter is optional. It specifies the integer that specifies the number of splits, items beyond the split limit will be excluded from the array. 

Return value:

Returns a new Array, having the split items.

Example: This example first converts the number to string then removes the portion before the decimal using the split() method. 

Javascript

let n = -2.50999974435;
console.log(n);

function GFG_Fun() {
    console.log((n + "").split(".")[1]);
}
GFG_Fun()

Output

-2.50999974435
50999974435

JavaScript Math.abs( ) and Math.floor( )

• Math.abs( ): The Math.abs() function in JavaScript is used to return the absolute value of a number. It takes a number as its parameter and returns its absolute value.
• Math.floor( ): The Math.floor() function in JavaScript is used to round off the number passed as a parameter to its nearest integer in a Downward direction of rounding i.g towards the lesser value.

Example: This example subtracts the floor of the number by original number to get the decimal portion. But in this case, we’ll get the exact portion after decimal. We’ll get the approximate result.

Javascript

let n = 2.57;
console.log(n);

function GFG_Fun() {
    n = Math.abs(n)
    console.log(n - Math.floor(n));
}
GFG_Fun()

Output

2.57
0.5699999999999998

Javascript indexOf() method

Using the indexOf() method to get the decimal part of the given number, in which we convert our number into a string and then get the index of the decimal point with the help of the indexOf() method. and then extract the part of the decimal string as a substring.

Syntax:

number.toString().indexOf(".")

Example:  In this example first we convert to the string and then get the index of the decimal point and store it in a new variable, and again convert the number into a string and get the decimal part using the substring() method.

Javascript

let number = 20.125;
let decimalValue = number.toString().indexOf(".");
let result = number.toString().substring(decimalValue+1);
//orignal number
console.log(number)
//Decimal part of Number
console.log(result);

Output

20.125
125