Arrays and Hashes

Even More Array Variable Assignment

• An array variable can appear in the list to the left of the equal operator, but it must be the last in the list, as it will be greedy and take the remainder of the values.
• Example:
  

  @First = (1, 2, 3, 4, 5); 
  ($One, $Two, $Three, @Rest) = @First; 
  print "One=$One, Two=$Two, Three=$Three\n"; 
  ==> One=1, Two=2, Three=3 
  print "@Rest\n"; 
  ==> 4 5 
  

• If a scalar variable is assigned equal to an array, then the scalar gets the current length of the specified array.
• Example:
  

  @First = (1, 2, 3, 4, 5); 
  $FirstLength = @First; 
  print "FirstLength = $FirstLength\n"; 
  ==> FirstLength = 5 
  

• Remember that in Perl, it is the operator being used that determines the variable type, not a variable declaration. Therefore, if you use an operator that requires a scalar context (as opposed to an array context), then you get the length of the array instead of the contents of the array.
• Example:
  

  @First = (1, 2, 3, 4, 5); 
  $theFirst = @First; # Scalar context so get length 
  print "theFirst = $theFirst\n"; 
  ==> theFirst = 5 
  ($theFirst) = @First; # Array context, so get first value, ditch rest
  print "theFirst = $theFirst\n"; 
  ==> theFirst = 1 
  

• Just like with scalars, the assignment operator for arrays returns the array being assigned. This allows chaining of assigments.
• Example:
  

  @First = (@second = (@Third = (1, 2, 3, 4, 5)));