home | O'Reilly's CD bookshelfs | FreeBSD | Linux | Cisco | Cisco Exam  


Book HomePerl CookbookSearch this book

4.9. Appending One Array to Another

Problem

You want to join two arrays by appending all the elements of one to the end of the other.

Solution

Use push :

# push
push(@ARRAY1, @ARRAY2);

Discussion

The push function is optimized for appending a list to the end of an array. You can take advantage of Perl's list flattening to join two arrays, but it results in significantly more copying than push :

@ARRAY1 = (@ARRAY1, @ARRAY2);

Here's an example of push in action:

@members = ("Time", "Flies");
@initiates = ("An", "Arrow");
push(@members, @initiates);
# @members is now ("Time", "Flies", "An", "Arrow")

If you want to insert the elements of one array into the middle of another, use the splice function:

splice(@members, 2, 0, "Like", @initiates);
print "@members\n";
splice(@members, 0, 1, "Fruit");
splice(@members, -2, 2, "A", "Banana");
print "@members\n";

This is output:





Time Flies Like An Arrow








Fruit Flies Like A Banana



See Also

The splice and push functions in perlfunc (1) and Chapter 3 of Programming Perl ; the "List Values and Arrays" section of Chapter 2 of Programming Perl ; the "List Value Constructors" section of perldata (1)


Previous: 4.8. Computing Union, Intersection, or Difference of Unique Lists Perl Cookbook Next: 4.10. Reversing an Array
4.8. Computing Union, Intersection, or Difference of Unique Lists Book Index 4.10. Reversing an Array

Library Navigation Links

Copyright © 2002 O'Reilly & Associates. All rights reserved.