Using functions

Functions are collections of statements that are grouped together and (optionally) have a name that we can use to call that function.

We’ve already used a few different functions. For instance console.log is a function. We call a function, which asks JavaScript to execute the statements within the function

Functions can accept input arguments, though not all functions require them.

If we use a function name without the ( ... ) we are referring to the function itself, if we add the ( ... ) then the function will be executed (or called).

Math

JavaScript has a Math object that contains a number of functions useful for doing … well, maths. You can see the full list of these functions in the Math documentation.

For example, calling Math.floor(x) and passing in a floating point number x will return the largest integer less than or equal to x.

// will return 3
Math.floor(3.2);

// will return 6
Math.floor(6.9);

// will return NaN
Math.floor();

// is a function
Math.floor;