Learn how to generate random number in javascript.
We are going to use Math.random() function to get a random number and then use it to generate another random number in any given range.
Math.random() method returns a random number between 0(inclusive) and 1(exclusive), represented as [0, 1) mathematically.
Which means it will return a random number like 0.9621987476689009 between the range 0 and 1 but it will never be 1. As this generated at core level there is very less probability of repeating the same number again.
Input: console.log(Math.random()); Output: 0.31203509541148966
We can use this randomly generated number along with Math.floor() to generate any random number in any given range.
Formula
(Math.floor((Math.random() * (max - min + 1)) + min));
Generate random number between 1 to 10 in javascript
We will multiply the randomly generated number with maximum - minimum + 1 and add minimum to it and take its floor to get the random number.
console.log(Math.floor((Math.random() * 10) + 1)); //4
Random number between 1 to 100
console.log(Math.floor((Math.random() * 100) + 1)); //20
Generate number between 5 to 25
console.log(Math.floor((Math.random() * (25 - 5 + 1)) + 5)); //23
Or we can create a custom function which will return the random number in any given range specified.
let randomNumber = (min = 0, max = 1) => { return Math.floor(Math.random() * (max - min + 1) + min); } console.log(randomNumber(85, 95)); //87
Generate random floating numbers in javascript
If we want to generate random number with decimals then there is another formula which can be used.
(Math.random() * (max - min) + min).toFixed(4);
You can update the toFixed to whatever precision you like.
console.log((Math.random() * (5.5 - 4.5) + 4.5).toFixed(4)); //"5.0633" //"4.9103" //"4.8354" //"5.0610"