Difference between revisions of "Return"

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(First 3 example are misleading and promote poor coding practices. Replaced with one example that illustrates the proper usage of the return keyword.)
 
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{{Multi-lang}}
{{LSL Header|ml=*}}
{{LSL Header|
{{#vardefine:name|return
}}{{#vardefine:name|return
}}{{#vardefine:p_value_desc|value or variable to be returned by the function, the type must be the same as that to be returned by the function.
}}{{#vardefine:p_value_desc|value or variable to be returned by the function, the type must be the same as that to be returned by the function.
}}{{#vardefine:header_title|return {{LSL Param|value}};
}}{{#vardefine:header_title|return {{LSL Param|value}};
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</div>
</div>
}}{{#vardefine:examples|
}}{{#vardefine:examples|
<pre>
<source lang="lsl2">
integer Goodbye()
string get_name(key uuid)
{
{
     llOwnerSay("Goodbye");
     return llKey2Name(uuid); // Returns the value of llKey2Name().
    return 0;
}
}


Hello()
// Usage within the script:
 
llOwnerSay("Name: " + get_name( llDetectedKey(0) ) ); // Tell owner what the name is.
 
</source>
 
 
 
<source lang="lsl2">
integer Calc (string cmd, integer a, integer b)
{
    // The user function has been declared as returning an integer,
    // so every return within the function must return an integer
    if (cmd == "+")    return a + b;
    // We don't need to code 'else' here, as the preceding statement resulted in 'return' when true
    if (cmd == "-")    return a - b;
    if (cmd == "*")    return a * b;
    if (cmd == "/")   return a / b;
    // We must return a value here too, we can't omit the final return
    return -1; 
}
default
{
{
     llOwnerSay("Hello");
     state_entry()
     return;
    {
        llSay(0, llList2CSV ( [ Calc("+",1,2), Calc ("-",5,3), Calc ("*",3,4), Calc("/",18,6) ] ) );
     }
}
}
</pre>
</source>
}}{{#vardefine:notes|
}}{{#vardefine:notes|
}}{{#vardefine:caveats|*There is a bug in the compiler and it will let you return a value with events, which when encountered at runtime will cause the script to crash.
}}{{#vardefine:caveats|*There is a bug in the compiler and it will let you return a value with events, which when encountered at runtime will cause the script to crash.

Latest revision as of 01:41, 5 March 2016

The correct title of this article is return. The initial letter is shown capitalized due to technical restrictions.

return value;

return value;
• type value value or variable to be returned by the function, the type must be the same as that to be returned by the function.

Used to return execution to the previous scope along with a value.

Functions

Exits the function and continues script execution in the previous scope.

Events

Causes the script to crash. Events cannot return a value. Use the next form of this keyword instead.

return;

Used to prematurely return execution to the previous scope before reaching the end of the function/event. You do not need to use this at the end of an event or function, as it is assumed by the compiler.

Functions

Exits the function and continues script execution in the previous scope.

Events

Exits the event and removes it from the event queue. If there is another event in the queue, that event is triggered.

Caveats

  • There is a bug in the compiler and it will let you return a value with events, which when encountered at runtime will cause the script to crash.
    • Do not try to return a value in the event scope if you do not wish your script to crash.

Examples

string get_name(key uuid)
{
    return llKey2Name(uuid); // Returns the value of llKey2Name().
}

// Usage within the script:

llOwnerSay("Name: " + get_name( llDetectedKey(0) ) ); // Tell owner what the name is.


integer Calc (string cmd, integer a, integer b)
{
    // The user function has been declared as returning an integer,
    // so every return within the function must return an integer
    if (cmd == "+")    return a + b;
    // We don't need to code 'else' here, as the preceding statement resulted in 'return' when true
    if (cmd == "-")    return a - b;
    if (cmd == "*")    return a * b;
    if (cmd == "/")    return a / b;
    // We must return a value here too, we can't omit the final return
    return -1;   
}
default
{
    state_entry()
    {
        llSay(0, llList2CSV ( [ Calc("+",1,2), Calc ("-",5,3), Calc ("*",3,4), Calc("/",18,6) ] ) );
    }
}

See Also

Keywords

•  jump
•  state