Declaring Functions
Functions, like variables, must be declared. Let"s declare a function double
that accepts an argument called x
and returns the double of x :
function double(x) {
return 2 * x;
}
Note: the function above may be referenced before it has been defined.
Functions are also values in JavaScript; they can be stored in variables (just like numbers, strings, etc ...) and given to other functions as arguments :
var double = function(x) {
return 2 * x;
};
Note: the function above may not be referenced before it is defined, just like any other variable.
Exercise
Declare a function named triple
that takes an argument and returns its triple.