[Cooltad]

I wish to know, which method is better?

new valid_weapon;

blah blah code..

valid_weapon=blahblah;

OR

blah blah code...

new valid_weapon=blahblah

[berni]

It's a common practice to allocate memory ressources at the top of the function/namespace. I think the reason is primarily the code layout,
and I think in the past the compilers didn't optimize allocations of variables inside loops etc. that well, but I don't think that's a problem nowadays anymore.
For none arrays variables I tend to use the 2nd example to save code lines.

[FaTony]

It also matter if you're have some if's and return's before the first call of variable. Why would you allocate memory for what may never be used?

PHP Code:

some code
if (!blahblah) {
   return;
   }
new variable=blahblah; 


[Dygear]

In pawn, not source:pawn, you have no choice. When you make a new variable you must use new, that token must be created with the new keyword before you can use said token.

New allows you to make a new variable, and if you don't set a value at time of creating the variable then it's automatically set to zero, there is no cost in setting the variable at creation to another value, in fact if you can, you should as this saves from making the same function call later.