Using undef to represent an unusual condition. : defined undef « Language Basics « Perl

1. Perl
2. Language Basics
3. defined undef

Using undef to represent an unusual condition.

    
#!/usr/local/bin/perl 

print ("Enter the number to divide:\n"); 
$value1 = <STDIN>; 
chop ($value1); 
print ("Enter the number to divide by:\n"); 
$value2 = <STDIN>; 
chop ($value2); 
$result = &safe_division($value1, $value2); 
if (defined($result)) { 
    print ("The result is $result.\n"); 
} else { 
    print ("Can't divide by zero.\n"); 
} 

sub safe_division { 
    local ($dividend, $divisor) = @_; 
    local ($result); 
    
    $result = ($divisor == 0) ? undef : 
    $dividend / $divisor; 
} 

   
    
    
    
  

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