php man page for array_intersect

ARRAY_INTERSECT(3)							 1							ARRAY_INTERSECT(3)

array_intersect - Computes the intersection of arrays

SYNOPSIS
       array array_intersect (array  $array1, array  $array2, [array  $...])

DESCRIPTION
       array_intersect(3)  returns  an	array  containing all the values of $array1 that are present in all the arguments. Note that keys are pre-
       served.

PARAMETERS
	      o $array1
		- The array with master values to check.

	      o $array2
		- An array to compare values against.

	      o $...
		- A variable list of arrays to compare.

RETURN VALUES
	Returns an array containing all of the values in $array1 whose values exist in all of the parameters.

EXAMPLES
       Example #1

	      array_intersect(3) example

	      <?php
	      $array1 = array("a" => "green", "red", "blue");
	      $array2 = array("b" => "green", "yellow", "red");
	      $result = array_intersect($array1, $array2);
	      print_r($result);
	      ?>

	      The above example will output:

	      Array
	      (
		  [a] => green
		  [0] => red
	      )

NOTES
       Note

	       Two elements are considered equal if and only if (string) $elem1 === (string) $elem2. In words: when the string	representation	is
	      the same.

SEE ALSO
       array_intersect_assoc(3), array_diff(3), array_diff_assoc(3).

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