Another "BCE0005: Unknown identifier:" error (following tutorial)

[GKdev1980]

I know it’s been discussed again and again, I’m just curious.

I’ve started the “Digital Tutors - Introduction to Scripting in Unity” tutorial series, still going through some basic stuff, at some point there’s a script when he first discusses custom functions:

function Update ()
{
if(Input.GetKeyUp(“space”))
{
WeaponSearch();
}
}

function WeaponSearch()
{
weapon = Random.Range(1, 5);

switch(weapon)
{
case 1:
	weaponName = "sword";
	DisplayMessage(weaponName);
	break;
case 2:
	 weaponName = "axe";
	 DisplayMessage(weaponName);
	 break;
case 3:
	weaponName = "dagger";
	DisplayMessage(weaponName);
	 break;
case 4:
	 weaponName = "bow";
	 DisplayMessage(weaponName);
	 break;
default:
	Debug.Log("You need to find a weapon!");
}

}

function DisplayMessage(weaponName)
{
Debug.Log("You found " + weaponName + “!”);
}

when I copy it and try to add it to a gameObject, I get an error
BCE0005: Unknown identifier: ‘weapon’. Now I’ve done some amateur coding in the past, I’m not completely new to some basic notions, I personally find it logical to get an error, since the variable is not declared earlier. I edited the line to:
var weapon = Random.Range(1, 5);
and it works just fine.

The thing is, that watching the video tutorial, he uses the unedited script and it works just fine (!!!). That is WITHOUT the “var” in front of the “weapon = Random.Range(1, 5);”. He get no errors or anything.

I’m wondering why is that. Does it have anything to do with the Unity version or anything? I go on, and he introduces us to loops with a statement:
for (i=1; i<5; i++);
without declaring the ‘i’ variable up ahead. And it works just fine!!

What exactly is going on?

[robertbu]

As an educated guess, I’ll bet you are using #pragma strict at the top of the file and the tutorial is not. There are sound performance and quality reasons for using #pragma strict and declaring your variables.

There is some reading here about static vs. dynamic typing and the implication for performance:

http://docs.unity3d.ru/ScriptReference/index.Performance_Optimization.html