PHP TIPS #4 – Array_diff_uassoc Function in PHP

Function Description:

array_diff_uassoc() function which compares two or more arrays while checking for differences before comparing the keys with a user-defined location. It then returns an array withthe keys and values from the first array(to which all the values were comapred against) it the function allows it.

Syntax is as follows : array_diff_uassoc(array1,array2,array3….,function).

with a sample below of how it is used.

function userdefined($v1,$v2)
{
if ($v1 === $v2)
{
return 0;
}
if ($v1 > $v2)
{
return 1;
}
else
{
return -1;
}
}
$a1=array(0=>”Dog”,1=>”Cat”,2=>”Horse”)
$a2=array(3=>”Dog”,1=>”Cat”,5=>”Horse”)
print_r(array_diff_uassoc($a1,$a2,”userdefined”));
?>

which results in the following output : Array( [0] => Dog [2] => Horse). For an example of the same function with two or more assigned arrays to the function:

function userdefined($v1,$v2)
{
if ($v1 === $v2)
{
return 0;
}
if ($v1 > $v2)
{
return 1;
}
else
{
return -1;
}
}
$a1=array(0=>”Dog”,1=>”Cat”,2=>”Horse”)
$a2=array(3=>”Dog”,1=>”Cat”,5=>”Horse”)
$a3=array(6=>”Onyx”,0=>”Dog”,5=>”Horse”)
print_r(array_diff_uassoc($a1,$a2,$a3,”userdefined”));
?>

Which in turn, gives you : Array ([2] => Horse )

So we see the different array_diff function variants and the diffeerent ways they are used to compare the values of one or more arrays with one another.