Re: [MacPerl] Novice question regards subroutines

[Brian "L." Matthews <blm@halcyon.com>]

>#!perl -wl
>$x = "one plus one";          #watch out for this one!
>print "yes" if $x = "two";    #Why does this work? The assignment succeeded,
>print $x;                            #so it's true.
>This works because of the /"$x = "two"/ part.
>This is always true, because it assigns the value succesfully.

No. The result of an assignment is the thing being assigned to (*not* the
value of the thing being assigned to), so the result of $x = "two" is $x.
This is then evaluated for the if, resulting in "two", which is a true
value, so "yes" is printed. This can be seen in John's example:

|#!perl -wl
|
|$x = "one plus one";
|print "yes" if $x = "";
|print "\$x is $x\n";

where the assignment is still successful, but "yes" isn't printed, because
when $x is evaluated for the if, it results in the empty string, which is
a false value.

|# Found = in conditional, should be ==.
|File 'Untitled'; Line 4
|$x is
|
|What I was expecting was no "Yes", but also no warning.

Why not? There's still an assignment in the conditional.

Brian

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