Recipe 4.10 Appending One Array to Another

4.10.1 Problem

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

4.10.2 Solution

Use push:

# push
push(@ARRAY1, @ARRAY2);

4.10.3 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 this 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")

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 the output:

Time Flies Like An Arrow
Fruit Flies Like A Banana

4.10.4 See Also

The splice and push functions in perlfunc(1) and Chapter 29 of Programming Perl; the "List Values and Arrays" section of Chapter 2 of Programming Perl; the "List Value Constructors" section of perldata(1)