Difference between revisions of "TRUE"
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Omei Qunhua (talk | contribs) (Comment on Boolean vs Integer, and use of the !! construct.) |
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|type=integer | |type=integer | ||
|value=1 | |value=1 | ||
|desc=Constant used to define the TRUE value in conditional structures or variables/constants in general. Usually it's used because it is more readable, indicating a [[Boolean|boolean]] value instead a [[Integer|integer]] value (1). | |desc=Constant used to define the TRUE value in conditional structures or variables/constants in general. Usually it's used because it is more readable, indicating a [[Boolean|boolean]] value instead a [[Integer|integer]] value (1). However, this is an arbitrary distinction in LSL which uses integers to represent Boolean values anyway. It is probably better to consider TRUE and FALSE as mnemonic constants for the integer values 1 and 0. | ||
|examples=<lsl>integer q; | |examples=<lsl>integer q; | ||
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|constants={{LSL ConstRow|FALSE}} | |constants={{LSL ConstRow|FALSE}} | ||
|functions= | |functions= | ||
|notes=*Note that all non-zero integers test as 'true' in statements such as "if (x) ... " but only the value 1 corresponds to TRUE as in "if (x == TRUE) ..." | |||
* A double exclamation mark can be used to convert any 'true' or FALSE integer to Boolean TRUE/FALSE as in "integer Bool = !!value;" | |||
|events= | |events= | ||
|articles={{LSL DefineRow||[[boolean]]|}} | |articles={{LSL DefineRow||[[boolean]]|}} | ||
Revision as of 04:41, 19 January 2013
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Description
Constant: integer TRUE = 1;The integer constant TRUE has the value 1
Constant used to define the TRUE value in conditional structures or variables/constants in general. Usually it's used because it is more readable, indicating a boolean value instead a integer value (1). However, this is an arbitrary distinction in LSL which uses integers to represent Boolean values anyway. It is probably better to consider TRUE and FALSE as mnemonic constants for the integer values 1 and 0.
Caveats
Examples
<lsl>integer q;
default {
state_entry()
{
q = TRUE;
if(q)
{
llSay(0, "TRUE");
q = FALSE;
if(!q)
{
llSay(0, "FALSE");
q = TRUE;
if(!q)
{
llSay(0, "Won't say this");
}
else
{
llSay(0, "TRUE");
q = FALSE;
if(q)
{
llSay(0, "Won't say this");
}
else
{
llSay(0, "FALSE");
}
}
}
else
{
llSay(0, "Won't say this");
}
}
else
{
llSay(0, "Won't say this");
}
}
}</lsl>
Notes
- Note that all non-zero integers test as 'true' in statements such as "if (x) ... " but only the value 1 corresponds to TRUE as in "if (x == TRUE) ..."
- A double exclamation mark can be used to convert any 'true' or FALSE integer to Boolean TRUE/FALSE as in "integer Bool = !!value;"