# Generate random integer between two numbers using JavaScript

Random number generation is the generation of a sequence of numbers or symbols that cannot be reasonably predicted better than by a random chance, usually through a random-number generator (RNG). Computer random number generators are important in mathematics, cryptography and gambling (on game servers).

In this article, we will be generating a random integer between given two numbers using JavaScript. We will be generating a random number in a given range using JavaScript Math Object.

We often need to generate a random number within a specified range in realtime applications. The logic dealt below can be very useful in situations like this.

### Fundamental Concept

`Math.floor(Math.random() * ((y-x)+1) + x);`

Math.random() returns a random number between 0 (inclusive) and 1 (exclusive).

Math.floor() rounds a number downward to its nearest integer.

### Generating JavaScript random number

CSS:

```.highlight{
color:green;
}```

HTML:

```<h1>Generate Random Number Using JavaScript</h1>
Random Number Between and
<input type=”button” value=”Get Number” onclick=”getRandomNumber();”>
<h2 class=”number”></h2>```

JavaScript:

```function getRandomNumberBetween(start,end){
return Math.floor(Math.random()*(end-start+1))+start;
}
function getRandomNumber(){
var start = document.getElementsByClassName('start').value;
var end = document.getElementsByClassName('end').value;
document.getElementsByClassName('number').innerHTML = 'The Random Number is : <span class="highlight">'+getRandomNumberBetween(parseInt(start),parseInt(end))+'</span>';
}```

In this way, we can generate random integer between two numbers using JavaScript.

You can follow the video for detail instructions and demo: