# JS Math object — some useful bits

I hate Maths (or Math as it’s known in some parts). I hate it because I’m rubbish at it, I don’t understand it, it does my head in, and it doesn’t excite me at all.

That said, I recently learned some stuff that the Javascript Math object can do that I can see I will use in the future, so I’m documenting it here.

**Math.min/Math.max**Find the lowest/highest number in a range

Math.min(1,20) //1

Math.max(5,90) //90

**Math.floor/Math.ceil**Round a floating point number down/up to the next integer

Math.floor(9.8768); //9

Math.ceil(8987.987); //8988

**Math.round**Round a floating point number to the nearest integer

Math.round(3.67); //4

**Math.random**

Return a random number between 0 and very close to 1, e.g.

Math.random() //0.7083173703867942

This means you can do this to get a random integer within a desired range:

function getRandomInt(min, max) {

return Math.floor(Math.random() * (max — min + 1)) + min;

}console.log(getRandomInt(10,50); //25

**Rounding**Not Math methods but hey…

toFixed(*n*) — round to *n* decimal places

35.980134701.toFixed(2); //35.98

toPrecision(*n*) — round to *n* precision

35.980134701.toPrecision(6); //35.9801

**isNaN**Check if a value is a number or not, returns true if

*not**a number*

//Prompt for an age until a number is given

do {

userAge = prompt("What's your age?");

} while (isNaN(userAge));