While poking around my thoughts about this node (Strange "Useless use of constant" message: should not appear at all!), I came across the fact that the warning messages seem to ignore '0's and '1's.

Example: (please ignore the fact that this code doesn't really do anything, it's meant to illustrate the warning messages only) 

#!/usr/bin/perl -w
use strict;

# Why the inconsistency with warning messages?
    my @movement = (0,1,2,3,4);
    my $from = "";
    if (@movement == (0,1,2)) {$from = "012"} # no warning
    if (@movement == (1,2,3)) {$from = "123"} # 1 warning
    if (@movement == (2,3,4)) {$from = "234"} # 2 warnings
    if (@movement == (3,4,5)) {$from = "345"} # 2 warnings

    if (@movement == (-0,-1,-2)) {$from = "012"} # 1 warning
    if (@movement == (-1,-2,-3)) {$from = "123"} # 2 warnings
    if (@movement == (-2,-3,-4)) {$from = "234"} # 2 warnings
    if (@movement == (-3,-4,-5)) {$from = "345"} # 2 warnings
    
    if (@movement == (0,1,0,1)) {$from = "0101"} # no warning
    if (@movement == (1,2,1,2)) {$from = "1212"} # 1 warning
    if (@movement == (2,3,2,3)) {$from = "2323"} # 3 warnings
    if (@movement == (3,4,3,4)) {$from = "3434"} # 3 warnings

[download]
Does anyone know why there are different numbers of warnings? (We expect one warning per number that gets thrown away within the list)
(i.e. it doesn't give warnings for any of the numbers in the list that it throws away if that number is a zero or one).

Does this affect anything that I do in my daily coding life? Not likely, I just wanna know 'cause I'm curious.

Sandy

UPDATE

Thanks to all the posters below. It's these little details that make learning stuff all the more interesting.

In reply to Warning messages about useless constants ignore '0's and '1's by Sandy

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