how to get only decimal value in js code example

Example 1: how to get decimal value in js

const number // Some Decimal Number
const decimal  = number - Math.floor(number)
//implementation
const number = 3.78;
const decimal = 3.78 - (Math.floor(3.78)) // Math.floor(3.78) returns 3
// decimal is 0.78

Example 2: obtain only integer not decimal js

var n = 5/3
n = Math.floor(n)
//This will return 1. 
//Math.floor returns a number less than or equal the number given