Tác dụng của hàm array_intersect()
The array_intersect() function compares the values of two or more arrays and returns the matches. The keys are not considered in the comparison, only the values are checked.
The following table summarizes the technical details of this function.
| Return Value: | Returns an array containing all the elements from array1 whose values are present in all of the other arrays. |
|---|---|
| Version: | PHP 4.0.1+ |
Syntax
The basic syntax of the array_intersect() function is given with:
The following example shows the array_intersect() function in action.
Example
Run this code »<?php
// Sample arrays
$array1 = array("apple", "ball", "cat", "dog", "elephant");
$array2 = array("alligator", "dog", "elephant", "lion", "cat");
// Computing the intersection
$result = array_intersect($array1, $array2);
print_r($result);
?>Parameters
The array_intersect() function accepts the following parameters.
| Parameter | Description |
|---|---|
| array1 | Required. Specifies the array to compare from. |
| array2 | Required. Specifies an array to compare against. |
| ... | Optional. Specifies more arrays to compare against. |
More Examples
Here're some more examples showing how array_intersect() function actually works:
The following example shows how to use this function to compare an array against two other arrays.
Example
Run this code »<?php
// Sample arrays
$array1 = array("apple", "ball", "cat", "dog");
$array2 = array("cat", "lion", "tiger");
$array3 = array("parrot", "cat");
// Computing the intersection
$result = array_intersect($array1, $array2, $array3);
print_r($result);
?>Two elements are considered equal if their string representation are same, i.e., (string) $elem1 === (string) $elem2. Let's take a look at the following example:
Example
Run this code »<?php
// Sample arrays
$array1 = array(1, 2, 5, 7, 11);
$array2 = array(0, "1", 2, 4, "07", 10);
// Computing the intersection
$result = array_intersect($array1, $array2);
print_r($result);
?>You can also use associative arrays, however the keys are not considered in the comparison.
Example
Run this code »<?php
// Sample arrays
$array1 = array("a"=>"red", "b"=>"green", "c"=>"blue", "d"=>"yellow");
$array2 = array("x"=>"black", "y"=>"blue", "z"=>"red");
// Computing the intersection
$result = array_intersect($array1, $array2);
print_r($result);
?>