PHP function introduction: array_intersect() function

PHP function introduction: array_intersect() function

In PHP, the array_intersect() function is used to compare the values ​​​​of two or more arrays and return a new An array containing all values ​​present in the input array.

Syntax
array_intersect(array1,array2,array3...)

Parameters

• array1: Required, the array used as a baseline for comparison.
• array2: Required, the array to be compared with array1.
• array3,...: Optional, other arrays to compare with array1.

Return value
Returns an array that contains all values ​​that exist in the input array.

Examples
Here are some examples of the array_intersect() function:

Example 1:

$array1 = array("apple", "banana", "orange", "grape");
$array2 = array("banana", "mango", "grape");
$result = array_intersect($array1, $array2);
print_r($result);

Output:

Array
(
    [1] => banana
    [3] => grape
)

Example 2:

$array1 = array(1, 2, 3, 4, 5);
$array2 = array(4, 5, 6, 7);
$result = array_intersect($array1, $array2);
print_r($result);

Output:

Array
(
    [3] => 4
    [4] => 5
)

Example 3:

$array1 = array("red", "green", "blue");
$array2 = array("green", "blue", "yellow");
$array3 = array("blue", "yellow", "pink");
$result = array_intersect($array1, $array2, $array3);
print_r($result);

Output:

Array
(
    [1] => green
    [2] => blue
)

Explanation
In example 1, $array1 contains "apple", " There are four elements: "banana", "orange" and "grape". $array2 contains three elements: "banana", "mango" and "grape". After comparing two arrays through the array_intersect() function, the resulting array contains values ​​that exist in both arrays, namely "banana" and "grape".

In Example 2, $array1 contains the numbers 1 to 5, and $array2 contains the numbers 4 to 7. After comparison through the array_intersect() function, the resulting array contains the values ​​that exist in both arrays, namely 4 and 5.

In Example 3, $array1, $array2 and $array3 contain different color values. After the array_intersect() function compares three arrays, the resulting array contains only color values ​​that exist in all three arrays, namely "green" and "blue".

Summary
The array_intersect() function is a very commonly used function in PHP, which can easily compare and extract common elements in multiple arrays. By rationally using this function, we can handle array-related logical issues more easily and improve development efficiency.

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