PHP array_intersect() Function

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# PHP array_intersect() Function

Complete PHP Array Reference

## Definition and Usage

The array_intersect() function compares two or more arrays, and returns an array with the keys and values from the first array, only if the value is present in all of the other arrays.

## Syntax

    array_intersect(array1,array2,array3...)

Parameter | Description
--- | ---
array1 | Required. The first array is the array that the others will be compared with
array2 | Required. An array to be compared with the first array
array3 | Optional. An array to be compared with the first array

## Tips and Notes

Tip: You can compare the first array with one array, or as many as you like.

Note: Only the value is used in the comparison.

## Example

    <?php
    $a1=array(0=>"Cat",1=>"Dog",2=>"Horse");
    $a2=array(3=>"Horse",4=>"Dog",5=>"Fish");
    print_r(array_intersect($a1,$a2));
    ?>

The output of the code above will be:

    Array ( [1] => Dog [2] => Horse )

Complete PHP Array Reference

From http://www.w3schools.com (Copyright Refsnes Data)