in reply to Re^3: Elegant way to return true or nothing from a subroutine?
in thread Elegant way to return true or nothing from a subroutine?

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Re^5: Elegant way to return true or nothing from a subroutine?
by fenLisesi (Priest) on Oct 10, 2006 at 12:20 UTC
    In the section "Returning Failure," PBP recommends using a bare return to signify failure. There is a two page discussion there, explaining that, at the hands of the caller, the returned undef can easily turn into the one-element list (undef) and evaluate to true. 
        sub foo { return undef;}
    sub bar { return;}
    if (my @foos = foo()) {
        print "foo() is so true...\n";  ## surprise!
    }
    else {
        print "foo() is false.\n"
    }
    if (my @bars = bar()) {
        print "bar() is true...\n";
    }
    else {
        print "bar() is false.\n"
    }

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