Arrays and Hashes

Yet More Array Element Access

• When taking a slice, any index can appear anywhere and as many times as you wish.
• Example:
  

  @First = (1, 2, 3, 4, 5); 
  @Second = @First[1,2,3,3,2,1]; 
  print "@Second\n"; 
  ==> 2 3 4 4 3 2 
  

• Slices can occur on either side of the assignment operator = .
• Example:
  

  @First = (1, 2, 3, 4, 5); 
  @First[0, 1, 2, 3, 4] = @First[4, 3, 2, 1, 0]; 
  print "@First\n"; 
  ==> 5 4 3 2 1 
  

• Using an index that is beyond the end of the array returns an undef.
• Assigning to an index that is beyond the end of the array automatically extends the array to include that value at that new index, and sets all other new elements between to undef.
• The construct $#ArrayName gives the index for the last element in array @ArrayName .
• A negative subscript in an array counts backwards from the end of the array.
• Example:
  

  @First = (1, 2, 3, 4, 5); 
  @First = @First[-1, -2, -3, -4, -5]; 
  print "@First\n"; 
  ==> 5 4 3 2 1