Javascript Random Number Generator – Random String Generator

In JavaScript Random Number Generator, I have explained how to generate a random number using Math.random() function.

Math.random() function returns floating-point number from 0(inclusive) to 1(exclusive).

I have covered below examples:
1).Generate a random number
2).Generate a random number between range
3).Generate a random number between negative and positive
4).Generate a random number with given length
5).Generate a random String

1). Generate a random number

function randomNumber(max)
{
	Math.floor(Math.random() * (max + 1));
}

To generate a random number less than or equal to 100(inclusive). Call randomNumber(100);.

 

2). Generate a random number in range

function randomNumberRange(min, max)
{
	return Math.floor(Math.random() * (max - min + 1) + min);
}

Note: min and max both are inclusive.

To generate a number between 1 to 100, Call randomNumberRange(1,100);

 

3) Generate a random number between negative and positive

To generate number between negative and positive also, we can use  randomNumberRange().

To generate a number between -5 to -1, Call randomNumberRange(-5,-1);

 

4). Generate a JavaScript random number with given length

You can use the below function, to generate JavaScript random number with given length

function randomNumberLen(len)
{
	var number ="";
	for(var i=0;i<len;i++)
	{
		number += randomNumberRange(0,9);
	}
	return number;
}

To generate a number with length 10, call randomNumberLen();

 

5). Generate a random string

You can use the below function , to generate random string with given length.

function randomString(len)
{
	var str ="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz1234567890";
	var randomStr='';
	for(var i=0;i<len;i++)
	{
		randomStr .= randomNumber(0,str.length-1);
	}

	return randomStr;
}

To generate a string with length 10, call randomString(10);

Reference: Mozilla Documentation