﻿ How to generate Random number in JavaScript - Math.random()

# How to generate Random number in JavaScript using Math.random()

You can use the Math.random() method in JavaScript to generate random numbers in a given range. Let’s see some examples.

## Syntax

Math.random()

The random() method does not take any parameter. It’s one of the many methods of Math object.

Here’s an example.

```<script>
let rndValue = Math.random();
document.write (rndValue);
</script>```

The method returns a random number in decimal values or floating number.

You can round off the random floating number using another Math method called round().

```let rndValue = Math.round(Math.random());
document.write (rndValue);```

## Random numbers between 0 and 50

Now, lets see how we can generate a random number in a given range between 0 and 50.

```<body>
<input type='button' id='bt' value='Generate Number' onclick='generate_random()' />
<p id='result'></p>
</body>

<script>
let generate_random = () => {
// generate random number between 0 and 50.

let rndValue;
rndValue = Math.floor((Math.random() * 50));

let p = document.getElementById('result');
p.innerHTML = rndValue;
}
</script>```

👉 You may also like this. Use Math.sign() method to check if a given number is negative or positive

## Generate Random numbers between 1 and 10

In the above example, the random() method returned numbers 0 and 50. You can ignore the Zero (0) and a generate number between 1 and a maximum number, like 1 to 10.

```<body>
<input type='button' id='bt' value='Generate Number' onclick='generate_random()' />
<p id='result'></p>
</body>

<script>
let generate_random = () => {
// generate random number between 1 and 10.

let rndValue;
rndValue = Math.floor((Math.random() * 10) + 1);

let p = document.getElementById('result');
p.innerHTML = rndValue;
}
</script>```

## Fun with Math.random() Method

Let’s have some fun with the random numbers that we’ll generate. I’ll use the random number to get the ASCII code of a character (or alphabet) in a given string (any string).

```<body>
<input type='button' id='bt' value='Click it' onclick='generate_random()' />
<p id='result'></p>
</body>

<script>
let generate_random = () => {
let rndValue;
rndValue = Math.floor((Math.random() * 10));

let p = document.getElementById('result');
p.innerHTML = 'Arun Banik'.charCodeAt(rndValue) + ' ' + 'Arun Banik'.charAt(rndValue);
}
</script>
</html>```

The method Math.random() works with all modern browsers including Internet Explorer.