[Newbies] "Print specific integers" Error message, how to improve and what causes that ?

[Ben Coman]

Okay, it looks like you did the work. So I'll offer an alternative.
Move the 'a' assignment to the top of the loop, immediately preceded by the
bounds check,
with the beneficial side-effect that the loop exits earlier.

myArray := #(2 32 44 67 89 111 123).
i := 1.
n := 1.
nMax := myArray size.
[ (i <=130) and: (n<=nMax) ] whileTrue:
[    a := myArray at: n.
    (i = a) ifTrue:
    [   Transcript show: i; cr.
        n := n +1.
    ].
].


> I think "array includes: i"  is nice. But I guess my way is faster.
Correct

yes. But is #includes: fast enough?  You are trading *one* line of code for
*ten*.
That makes  #includes:  faster write, so you stay more in-the-zone of your
application domain,
and forever-after makes it faster to understand every time your read your
code.

You should avoid premature optimisation, and only use your implementation
once benchmarks show its a problem.

cheers -ben

On 17 November 2017 at 10:57, RedTigerFish <chihuyu at gmail.com> wrote:

> *Update:*
>
> I found another way to solve this issue:
>
> |myArray|
>
> myArray := #(2 32 44 67 89 111 123).
>
> n := 1.
> a := myArray at: n.
>
> 1 to: 130 do: [:i|
>     i = a
>     ifTrue: [
>         Transcript show: i; cr.
>         n := n +1.
>         a := myArray at: n.
>         n = 7
>         ifTrue: [n := n - 1].
>         ].
>     ].
>
>
> *Looks ugly though*
>
>
>
> -----
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> Down below's well.
> Let those that walk in darkness shout,
> Down below's hell.
> --
> Sent from: http://forum.world.st/Squeak-Beginners-f107673.html
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