# SPUG: create a array which is XOR of two arrays

Chris Cantrall chris_cantrall at yahoo.com
Mon Oct 23 14:51:50 PDT 2006

```Quoting the FAQ:

How do I compute the difference of two arrays? How do I compute the intersection of two arrays?

Use a hash. Here's code to do both and more. It assumes that each element is unique in a given array:

@union = @intersection = @difference = ();
%count = ();
foreach \$element (@array1, @array2) { \$count{\$element}++ }
foreach \$element (keys %count) {
push @union, \$element;
push @{ \$count{\$element} > 1 ? \@intersection : \@difference }, \$element;
}

Note
that this is the symmetric difference, that is, all elements in either
A or in B but not in both. Think of it as an xor operation.

perlfaq4

http://perldoc.perl.org/perlfaq4.html#How-do-I-compute-the-difference-of-two-arrays%3f--How-do-I-compute-the-intersection-of-two-arrays%3f

HTH.

----- Original Message ----
From: Sachin Chaturvedi <sachin_chat at coolgoose.com>
To: spug-list at pm.org
Sent: Monday, October 23, 2006 12:41:23 AM
Subject: SPUG: create a array which is XOR of two arrays

i have two arrays
@array1 = { t1, t2 , t3 }
@array2 = ( t1 , t2 , t5, t7, t8}
i want to create a new array which has all elements of array2 such that they
are not in array1.
i mean my final array should be
@final = {t5,t7,t8}
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```