Re^2: Range Operator in If Statement

[mmartin]

Hey perlbotics, thanks for you QUICK reply...

Ohh ok I thought I could use the range operator for this type of thing, but guess not.

I wanted to use that because it seemed like it was the "shorthand" way of doing it.
Wanted a short way because I needed a whole bunch of those statements and I didn't want to have a ton of these statements:

if ($ref >= 1 && $ref <= 8) { ...... }
if ($ref >= 9 && $ref <= 16) { ...... }
if ($ref >= 17 && $ref <= 24) { ...... }
if ($ref >= 25 && $ref <= 32) { ...... }
#....more checks

But if that's what you recommend then I'll just use my original way I had like above and like you had...

Thanks again for the reply,
Matt

[Marshall]

This looks like a power of 2 problem. If you could give us some more detail about what you are doing, I think some very efficient solutions might be forthcoming.

[LanX]

When classifying by intervals, better try $case = int( ($ref-1) / 8 ) , so you only have to test for the results 0,1,2,3...

DB<104> for $ref (1,8,9,16,17,24,25,32) { print "$ref: ", int(($ref-1)
+/8), "\n" } 
1: 0
8: 0
9: 1
16: 1
17: 2
24: 2
25: 3
32: 3

[ambrus]

If you have multiple consecutive intervals, it's better to use an elsif cascade, such as

if ($ref <= 8) { 
        say "ref is at most 8.";
} elsif ($ref <= 16) {
        say "ref is above 8 but at most 16."
} elsif ($ref <= 24) {
        say "ref is above 16 but at most 24."
} elsif ($ref <= 32) {
        say "ref is above 24 but at most 32."
} else {
        sat "ref is above 32."
}

The elsif part means that if the previous condition was found true, the next one is not tested for, so eg. if $ref = 5 then the first branch is executed, the rest of the tests and branches are skipped.