Do you use "this" or use "_" ?

Hi, while playing around in CS4 and coding with as3, on some custom made class I came across a pro... an annoyance.

First is the reserved keywords, which, if you want to follow some good coding guidelines, you will not use the such as "height" "width" "size" as a property name.

Second, if a parameter variable holds the same name as a class property (which occurred as I wanted to keep variable names simple and self-descriptive).

So to distinct the 2 variable names above, the use of "this" or altering the name of the property by adding an underscore "_" is required.

So it got me wondered if I should just keep my property names as I see fit, simple and relevant, and force myself to make the use of "this" all the time as a coding practice, or, not bother with using "this" but bother with always using the "_" instead.

I'd like to hear the point of view that you veterans have here.

Personally, I use "this." to distinguish class member properties from parameter names when they would otherwise collide. Many people use a preceding underscore to indicate that a variable is private, and other people always use the underscores for function parameter names. Pick a style and stick to it. I don't believe there is an established standard for function parameter naming schemes.

i'll occasionally let arguments bump property names

PHP Code:

---

private var wide:Number;
private var tall:Number;
public function Box(wide:Number,tall:Number):void{
  this.wide = wide;
  this.tall = tall;
} 


---

but would never let a variable share a name as a class member. i use underscore only for private variables that're going to have a getter/setter

PHP Code:

---

private var _wide:Number;
public function get wide():Number{
  return _wide;
}
public function set wide(value:Number):void{
  _wide = value;
  // do other stuff
} 


---

other than that, i don't use underscores or dollar signs or anything like that... even at the cost of verbosity, i'll preserve the uniqueness of members

but like 5tons said, it's really just preference

Another vote for the "this." prefix.

It should be noted that the "this." prefix is implicitly added whenever you access any member variable or member function from within the object. The only time it makes a difference is when a class member is shadowed, so you don't have to use it unless that's happening.

My personal preference is to always use the prefix, even when unnecessary. The prefix tends to indicate a side-effecting operation and, at the same time, a member function which never uses a class member is a red flag, so adherence to such a rule makes those cases more obvious, etc.