19. Function Expression Recap

What you've learned so far:

Function Expression: When a function is assigned to a variable. The function can be named, or anonymous.
Use the variable name to call a function defined in a function expression.

// anonymous function expression
var doSomething = function(y) {
  return y + 1;
};

// named function expression
var doSomething = function addOne(y) {
  return y + 1;
};

// for either of the definitions above, call the function like this:
doSomething(5);

Returns: 6

You can even pass a function into another function inline. This pattern is commonly used in JavaScript, and can be helpful streamlining your code.

// function declaration that takes in two arguments: a function for displaying
// a message, along with a name of a movie
function movies(messageFunction, name) {
  messageFunction(name);
}

// call the movies function, pass in the function and name of movie
movies(function displayFavorite(movieName) {
  console.log("My favorite movie is " + movieName);
}, "Finding Nemo");