Switch
Syntax
| Syntax legend | |
|---|---|
| < ... > | item |
| [ ... ] | optional |
| ( ... ) * | 0 or more times |
| ( ... ) + | 1 or more times |
Switch ( <value> )
- ( Case <value> :
- [ <code> ]
- End ) *
- [ Default:
- [ <code> ]
- End ]
End
Description
A Switch is used to control the flow of a program by means of comparing a value to other values and executing the code associated with the correct value.
switch ( <value> )
case <value1>:
// code1
end
case <value2>:
// code2
end
default:
// code3
end
end
When the switch is reached it will compare value with the values in the cases, going from top to bottom. When a case matches, that code is executed and the switch is exited. This is different than the switch in C and probably more languages, because there the switch is only exited when a break is reached or when the switch ends. In Bennu there is no break; for the switch, though.
A value in a case can also be a range: <lowervalue>..<uppervalue>. Both the lowervalue and the uppervalue are part of the range.
You can also specify multiple values in a case, separated by a comma: <value1>,<value2>,.... These values can also be ranges.
Example
A scoretext function. Notice the default: when the points can be 0..100, that code should never be executed. However, an error can occur and blurting an error to the user is not that fancy, so this is a way of showing to the programmer there is an error, but still the user gets some message. In such cases, default can be handy. Of course that code could just as easily have been put under the switch with the same result, in this case, because every case does a return.
Function String scoretext( int points )
Begin
Switch( points )
Case 100:
return "1337 |-|4><0|2!!1";
End
Case 90..100:
return "Awesomely cool, dude!";
End
Case 80..90:
return "You're getting the hang of it!";
End
Case 60..80:
return "Not too shabby, mate.";
End
Case 50..60:
return "Practice some more.";
End
Case 30..50:
return "Dude...weak.";
End
Case 1..30:
return "That's just awful";
End
Case 0:
return "No points? n00b!";
End
Default:
return "I dunno what you did, but...";
End
End
End