How can I compare the rows in two 2d arrays? [duplicate] - php

Question

This question already has answers here:
Get difference between associative rows of two 2-dimensional arrays
(5 answers)
Closed last year.
It seems that every PHP function I read about for comparing arrays (array_diff(), array_intersect(), etc) compares for the existence of array elements.
Given two multidimensional arrays with identical structure, how would you list the differences in values?
Example
Array 1
[User1] => Array ([public] => 1
[private] => 1
[secret] => 1
)
[User2] => Array ([public] => 1
[private] => 0
[secret] => 0
)
Array 2
[User1] => Array ([public] => 1
[private] => 0
[secret] => 1
)
[User2] => Array ([public] => 1
[private] => 0
[secret] => 0
)
Difference
[User1] => Array ([public] => 1
[private] => 0 //this value is different
[secret] => 1
)
So my result would be - "Of all the users, User1 has changed, and the difference is that private is 0 instead of 1."

Answer 1

One way is to write a function to do something similar to this..
function compareArray ($array1, $array2)
{
foreach ($array1 as $key => $value)
{
if ($array2[$key] != $value)
{
return false;
}
}
return true;
}
You could easily augment that function to return an array of differences in the two..
Edit - Here's a refined version that more closely resembles what you're looking for:
function compareArray ($array1, $array2)
{
var $differences;
foreach ($array1 as $key => $value)
{
if ($array2[$key] != $value)
{
$differences[$key][1] = $value;
$differences[$key][2] = $array2[$key];
}
}
if (sizeof($differences) > 0)
{
return $differences;
}
else
{
return true;
}
}

Answer 2

I think this does what you're looking for.
Using your sample data, doing a loop on the outer arrays, then using array_diff_assoc on the users each time through. (Note, this assumes that when there's a difference, array_diff_assoc returns the value from the second array passed in, which it seems to do).
<?php
$user1 = array("public" => 1, "private" => 1, "secret" => 1);
$user2 = array("public" => 1, "private" =>1, "secret" => 1);
$array1 = array ("user 1"=>$user1, "user 2"=>$user2);
$user1 = array("public" => 1, "private" => 0, "secret" => 1);
$user2 = array("public" => 1, "private" => 1, "secret" => 1);
$array2 = array("user 1"=>$user1, "user 2"=>$user2);
$results = array();
foreach ( $array1 as $user => $value )
{
$diff = array_diff_assoc( $array1[$user], $array2[$user] );
if ($diff) {
array_push($results,array($user=>$diff));
}
}
print_r($results);
?>
It returns:
Array
(
[0] => Array
(
[user 1] => Array
(
[private] => 1
)
)
)

Answer 3

Try this function:
function arrayDiff($array1, $array2)
{
if (!is_array($array1) || !is_array($array2)) {
return false;
}
foreach ($array1 as $key => $val) {
if (array_key_exists($key, $array2) && gettype($val) != "array" && $val === $array2[$key]) {
unset($array1[$key]);
continue;
}
if (is_array($val)) {
$val = diff($val, $array2[$key]);
if ($val !== false) {
$array1[$key] = $val;
}
}
}
return $array1;
}
$array1 = array(
array(
array('foo', 'bar', 'baz'),
0
)
);
$array2 = array(
array(
array('foo', 'bar')
)
);
var_dump(diff($array1, $array2));

Answer 4

If you're looking for differences in the values, how about array_diff_assoc. The http://us2.php.net/manual/en/function.array-diff-assoc.php">php manual says it "returns an array containing all the values from array1 that are not present in any of the other arrays" and gives the following example:
In this example you see the "a" =>
"green" pair is present in both arrays
and thus it is not in the ouput from
the function. Unlike this, the pair 0
=> "red" is in the ouput because in the second argument "red" has key
which is 1
<?php
$array1 = array("a" => "green", "b" => "brown", "c" => "blue", "red");
$array2 = array("a" => "green", "yellow", "red");
$result = array_diff_assoc($array1, $array2);
print_r($result);
?>
The above example will output:
Array
(
[b] => brown
[c] => blue
[0] => red
)
Is this what you're looking for?