All posts tagged ‘Programming’

File Under: Glossary


Events are user interactions with their computer, such as a mouse click or key press.

In the good ol’ days, computers handled user interactions as input of batched data. The user fed a hunk of data in, the computer did something to that data, then produced the results. With the advent of interactive devices like the GUI interface, computers could display answers to computations onscreen. The input for these interactions are events caused by the user, which could be keystrokes, button clicks, or the position of the mouse pointer. (see Event Handler).

File Under: Glossary


In JavaScript, expressions are phrases that the interpreter can evaluate. For example,

x + 10
x < 10
are expressions since they can be evaluated, while
x = 10
is simply a statement.

In linguistical terms, JavaScript is made up of sentences, phrases, and words. The sentences are JavaScript statements, in which an entire action is expressed. The phrases are JavaScript expressions, in which the elements of the action can be created and put together to make a statement. The words are JavaScript operators, which are used to act upon the data passed to them.

File Under: Glossary


A function is a named group of statements in a program that performs a task when it is invoked.

Other programming languages make a distinction between a function, which returns a value, and a procedure, which performs some operation but does not return a value. Since JavaScript does not make this distinction, you can create functions that return values elsewhere in your code.

File Under: Glossary


A hash, also known as an associative array, is a collection of data in which each piece of data has two components: a key and a value. Much like the hash at your local diner, JavaScript hashes go unordered: They’re not indexed by numbers. For example, if you wish to use JavaScript to put up a different GIF animation on your site every day of the week, you might throw all these animations into a hash associated to each weekday as a key. Then you would refer to the key day to invoke that day’s animation.

For example, in a normal array, you’d have:

  dinner[0] = "monkey brain";

  dinner[1] = "meatloaf";

But in a hash, you could use a string as the index:

  dinner["monday"] = "monkey brain";

  dinner["tuesday"] = "meatloaf";

File Under: Glossary


Much like standing behind your co-worker while she slaves away, hover implies standing by but not doing anything. In dHTML, it refers specifically to when the user has positioned her cursor over a link but not yet clicked anything. The style will not change if the cursor is simply passed over the link, but you can set an action to take place after a predetermined amount of hovering.