We’ve all seen it, perhaps even in our own code. It’s something I think we do because we’re not really sure what would happen if we didn’t do it. Here are some little tidbits of pointless code I’ve been seeing recently:

For starters, here’s a quick review of the default values of class fields:

class Classy
{
    public var i:int; // 0
    public var u:uint; // 0
    public var n:Number; // NaN
    public var s:String; // null
    public var o:Object; // null
    public var a:Array; // null
    public var b:Boolean; // false
    public var r:RegExp; // null
    public var v:Vector.<int>; // null
}

Make sure you know the above. When you do, you realize how pointless and bloated this is:

class Classy
{
    public var i:int = 0
    public var u:uint = 0
    public var n:Number = NaN
    public var s:String = null
    public var o:Object = null
    public var a:Array = null
    public var b:Boolean = false
    public var r:RegExp = null
    public var v:Vector.<int> = null
}

All of these assignment statements will result in bytecode that gets executed to change each variable to its current value. This wastes CPU cycles and increases the size of your SWF. It should be noted though that constants do require initialization.

The second and last case I’ll talk about today is the case of conditionals. Any expression you put in an if or the like will essentially be passed to the global Boolean function. Consider these if statements:

// Best at everything except being explicit
if (obj)
{
}
// Explicit, more typing, slow
if (obj != null)
{
}
// Sort of explicit, even more typing, slowest
if (Boolean(obj))
{
}

Keep this in mind as you write your conditionals. As a programmer you’re likely to type a lot. Make sure your typing really counts!