nice wrote:
Canol Gokel wrote:
Hello,
Is there a way to exit loops if a condition is met? For example:
1 to: 10 do: [:x |
x = 3 ifTrue: [
...
]
]
What should I write instead of three dots to exit the loop if x is
equal to 3?
Usual ways to do it:
1) put a return instruction in the ifTrue: block
However, the interpreter will exit the current method and not execute
instructions after the to:do:...
2) use some kinf of detect:ifNone: trick
(1 to: 10) detect: [:x | x = 3 or: [... false.]] ifNone: [].
Unusual way:
3) do it with an Exception.
Create a new Exception subclass, say ExitLoop.
Then write:
[1 to: 10 do: [:x | x = 3 ifTrue: [ExitLoop raise] ...]]
on: ExitLoop do: [:exc | exc return: nil].
Nicolas
Forgot a usual fourth way:
4) use a Stream.
exit := false.
stream := (1 to: 10) readStream.
[ exitLoop or: [stream atEnd]]
whileFalse: [| x |
x := stream next.
x = 3
ifTrue: [exit := true]
ifFalse: [...]].
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