LSL Constants vs Globals

There are some advantages in using global variables over the string and key constants; it's faster and uses less bytecode when it is longer than 3 characters and is used more than twice, but it uses more bytecode when it is shorter than 3 characters or is used once. This is easily demonstrated by running the scripts in Figure 1.

Pros

Faster
Uses less bytecode when it is longer than 3 characters and it used more than twice.

Cons

User can accidentally change the value.
Uses more bytecode when it is shorter than 3 characters or it used once.

Figure 1: Bytecode Cost

Constant

Global

<lsl>

dead(){

   key a = NULL_KEY;
   key b = NULL_KEY;
   key c = NULL_KEY;
   key d = NULL_KEY;

}

default {

   state_entry() {
       llOwnerSay((string) llGetFreeMemory());
   }

}</lsl>

<lsl>key null_key = NULL_KEY;