Function Expressions

Function declarations

function catSays(max) {
  //function contents
}

catSays();

Function expressions

var catSays = function(max) {
  //function contents
};

catSays();

Once you know how to declare a function, a whole new set of possibilities will open up to you.

For instance, remember how you can store anything you want in a variable? Well, in JavaScript, you can also store functions in variables. When a function is stored_inside_a variable it's called afunction expression.

var catSays = function(max) {
  var catMessage = "";
  for (var i = 0; i < max; i++) {
    catMessage += "meow ";
  }
  return catMessage;
};

Notice how thefunctionkeyword no longer has a name.

var catSays = function(max) { 
  // code here 
};

It's ananonymous function, a function with no name, and you've stored it in a variable calledcatSays.

And, if you try accessing the value of the variablecatSays, you'll even see the function returned back to you.

catSays;

Returns:

function(max) {
  var catMessage = ""
  for (var i = 0; i < max; i++) {
    catMessage += "meow ";
  }
  return catMessage;
}