Re: Challenge - Creative Way To Detect Alpha Characters

This is both perl-specific and slow, but I'll just show it:

sub isalpha { 
    no warnings "numeric";
    my($p) = @_;
    0==++$p; 
}
sub hasalpha { 
    my($s) = @_;
    isalpha(substr($s, 0, 1, "")) and return 1 while 
        length($s);
    return; 
};
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Comment on Re: Challenge - Creative Way To Detect Alpha Characters Download Code

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Re^2: Challenge - Creative Way To Detect Alpha Characters by Pragma (Scribe) on Sep 14, 2004 at 07:37 UTC
You could hit it from the back {g}: `sub hasalpha { local($_) = @_; isalpha chop and return 1 while length; return; }` [download]	[reply] [d/l]
Re^2: Challenge - Creative Way To Detect Alpha Characters by Jasper (Chaplain) on Sep 14, 2004 at 10:17 UTC
Shurely shome mishtake. This returns true for anything other than 0-9, doesn't it? Is that what the OP wanted? My solution, slightly similar to one of the others: `$range[ chop ] = 1 while $_; # $_ is copy :) grep $_, @range[65..90,97..122];` [download] Did someone mention efficiency (I hope not)?	[reply] [d/l]
Re^3: Challenge - Creative Way To Detect Alpha Characters by ambrus (Abbot) on Sep 14, 2004 at 15:40 UTC
No. The isalpha function I gave returns true only for `[a-zA-Z]` characters, false on numbers, punctation, international letters, or any other character. It seems to give the same results for me than `lc ne uc`: `sub isalpha { no warnings "numeric"; my($p) = @_; 0==++$p; } sub hasalpha { my($s) = @_; isalpha(substr($s, 0, 1, "")) and return 1 while length($s); return; }; @t = ("f/2", "-2/", "*+)", "165", "foop", " A="); $\=$/; $,=" "; print grep hasalpha($_), @t; print grep lc ne uc, @t;` [download] outputs `f/2 foop A= f/2 foop A=` [download] This is because if $p is a non-alnum character in the isalpha function, $p++ converts it to a numeric 0 first, than it increases it to 1, so `0==$p++` is false.	[reply] [d/l] [select]
Re^3: Challenge - Creative Way To Detect Alpha Characters by Pragma (Scribe) on Sep 14, 2004 at 18:42 UTC
Your forgot to ord before you chop.	[reply]