Difference between revisions of "NULL KEY"

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Despite fitting the syntax criteria to be a valid [[key]], when fed to a {{LSLGC|Conditional}} as a key it executes as false.
 
Despite fitting the syntax criteria to be a valid [[key]], when fed to a {{LSLGC|Conditional}} as a key it executes as false.
  
In most applications NULL_KEY isn't needed; an empty string will suffice.
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Some people say that in most applications NULL_KEY isn't needed, and that an empty string ( "" ) will suffice. Others say that doing so is bad style, can cause hard-to-track-down bugs in your script, and might be unsupported in future code releases.
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|examples=
 
|examples=
 
<lsl>
 
<lsl>

Revision as of 20:24, 7 July 2008

Description

Constant: string NULL_KEY = "00000000-0000-0000-0000-000000000000";

The string constant NULL_KEY has the value "00000000-0000-0000-0000-000000000000"

While technically a string constant, it is only useful as a key.

Despite fitting the syntax criteria to be a valid key, when fed to a Conditional as a key it executes as false.

Some people say that in most applications NULL_KEY isn't needed, and that an empty string ( "" ) will suffice. Others say that doing so is bad style, can cause hard-to-track-down bugs in your script, and might be unsupported in future code releases.

Related Articles

Functions

•  llAvatarOnSitTarget
•  llDetectedKey
•  llGetNotecardLine
•  llGetLandOwnerAt
•  llGetPermissionsKey
•  llGetTexture
•  llListen

Events

•  attach

Examples

<lsl> integer isKey(key in) {

   if(in) return 2;
   return (in == NULL_KEY);

}//returns 2 if it's a valid key, 1 if it's NULL_KEY </lsl>

Notes

Like any LSO string constants longer then 3 characters and used in multiple places in the code, they should be stored in a global variable. The result will be a considerable memory savings. This does not apply to scripts compiled with Mono. See LSL Constants vs Globals for more information about this and examples.
test

Deep Notes

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Signature

string NULL_KEY = "00000000-0000-0000-0000-000000000000";