Can You Use `array_unique` with Objects to Remove Duplicates?

Using array_unique with Objects

Arrays are a fundamental data structure in programming, and there are often operations that need to be performed on them. One common operation is removing duplicate elements. For arrays of primitive data types, the array_unique function can be used. However, when dealing with objects, things become a bit more complex.

Problem

Imagine you have several arrays containing Role objects that need to be merged and then deduped. Is there a way to achieve this using a method similar to array_unique that is specifically designed for objects?

Solution

Yes, it is possible to use array_unique with objects by specifying the SORT_REGULAR flag. This will compare the objects based on their properties, rather than object identity.

<code class="php">class MyClass {
    public $prop;
}

$foo = new MyClass();
$foo->prop = 'test1';

$bar = $foo;

$bam = new MyClass();
$bam->prop = 'test2';

$test = array($foo, $bar, $bam);

print_r(array_unique($test, SORT_REGULAR));</code>

Output:

Array (
    [0] => MyClass Object
        (
            [prop] => test1
        )

    [2] => MyClass Object
        (
            [prop] => test2
        )
)

Important Note:

When using array_unique with objects, it's important to note that it uses the "==" comparison, not the strict comparison ("==="). This means that two objects with identical properties but different object identities will not be considered duplicates. Therefore, if strict comparison is required, an alternative approach may be necessary.

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