Arrays and Hashes

Common Hash Functions: Keys

• The keys(%Hashname) returns a list of all the current keys in a given hash.
• Note that you could do this exact same thing by creating an array from a hash, and returning all the odd numbered (even indexed) elements.
• Example:
  

  $Results{"Bill"} = 1000; 
  $Results{"Bob"} = "forfeit"; 
  $Results{"Betty"} = 6000; 
  @myArray = keys(%Results); 
  print "Keys in hash are @myArray"\n"; 
  ==> Keys in hash are Bob Bill Betty 
  

• Warning! The keys function in a scalar context gives the number of keys in the hash.
• Example (continuing above):
  

  print "Keys in hash are " . keys(%Results) . "\n";
  ==> Keys in hash are 3