Random Math Javascript

absolute | absolute value | exp | floor | JavaScript | log | mean | ones | sin | square | square root

Michael Zippo 04.11.2021

To create a random number in Javascript, the math.random () function is used. JavaScript math.random () generates a random decimal value between 0 and 1. The function takes no arguments. To get random numbers greater than 1, simply multiply the result as needed.

In programming, there are often times when you need to get a random number. For example, you can create a puzzle and want your program to generate a random number each time the user runs the program. Or you might want to run a function a random number of times.

This is where the Math.random () JavaScript function comes in. Math.random () is a built-in method that can be used to generate random numbers in JavaScript. The function returns a value between 0 (inclusive) and 1 (excluded), but we can use another function called Math.floor () to turn our number into a random integer.

In this tutorial, we’ll explore the basics of JavaScript random number generation and discuss how you can use the Math.random () function in your code.

JavaScript Math Refresher

The JavaScript Math object provides developers with a set of mathematical functions that can be performed on numbers. These functions include returning the absolute value of a number, rounding a number, calculating the square root of a number, and more.

The Math object works with the Number data type in JavaScript. This is what the Math object looks like in a JavaScript program:

Math.functionName ();


One of the most useful functions in the Math library - and the one we’ll use later in this tutorial - is the Math.floor () function. This method can be used to return a value rounded to the nearest whole number or lower whole number. Here is an example of the Math.floor () method in action:

console.log (Math.floor (5.7));


Our code returns: 5. The number Math.floor () the processed function has been rounded to lower, that’s why our program returned "5" instead of "6".

Similarly, the Math.round () function can be used to round a number down closer Here is an example of the Math.round () function in action:

console.log (Math.round (5.7));


Our code returns: 6. The Math object includes a number of other math functions that can be used to work with numbers, but the main ones need to be known to generate a JavaScript random numbers are Math.floor () and Math.random ().

JavaScript Math.random ()

The JavaScript math.random () return and a number random between 0 (inclusive) and 1 (exclusive ). The Math.random () function returns a pseudo-random floating point number, which means it will include one decimal place. The syntax of the Math.random () method is as follows:

Math.random ();


Here is an example console.log () used to print a random number:

Our program returns:

0.022831222528214346


As you can see, our program returned a random number between zero and one. But this number is quite small, and many applications that require random numbers want to generate larger numbers. This is where the Math.floor () function comes in.

We can use the Math.floor () function to round our random number so that it becomes a random integer and we can multiply that number by generating a bigger one. Here is an example of a random number generation function in JavaScript:

Here is the result of our program after running it three times:

As you can see, our program generated a random number. In the example above, we used " * 10 " to generate a larger number. This function helps us to retrieve a number between "1" and "10." If we wanted a bigger number, we could change our multiple like this:

After running our program three times, the following numbers were generated:

So let’s say we create an addition set and we want to generate two random numbers between" 1 " and" 100 " for our additional sum to be understood. We could use the following code to generate our random numbers:

Our program returns: