Hi Monks,

I encounter some trouble when I try to dispatch function via hash:

sub write_flag{
    print "Success for flag.\n";
}
sub write_sets{print "Success for Set.\n"; }
sub do_nothing{print "Exit Here\n";}
my %Op = (
    set_to_flag => \&write_flag,
    set_tree => \&write_sets,
    default => \&do_nothing
);
sub build_sth{
    my ($op_code) = @_;
    print "\n\nCode: $op_code:\n";
    my $op_exec = $Op{$op_code} ;
    if(defined($op_exec)){
        print "it exist: $op_exec\n";
    }else{
        print "Oop\n";
    }

}

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If I call the build_sth like this: 
build_sth('set_to_flag');

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It give me: 
Oop

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If I try to execute the function reference (by &$op_exec()) in build_sth, I will get: 
Can't use string ("") as a subroutine ref while "strict refs" in use a
+t ...

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What happened? How can I get it works?

In reply to Function reference undef when extract from hash? by Anonymous Monk

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