How to learn PHP array_intersect_key()_PHP tutorial

How to learn PHP array_intersect_key()

Definition and usage

The array_intersect_key() function calculates the intersection of arrays using key name comparison.

array_intersect_key() returns an array containing the values ​​of all key names that appear in the compared array and appear in all other parameter arrays.

Note: Only key names are used for comparison.

Grammar

array_intersect_key(array1,array2,array3...)

Parameters

Description

array1 required. The first array to compare with other arrays.

array2 required. The array to compare to the first array.

array3 is optional. The array to compare to the first array. There can be multiple.

Example 1

"Cat",1=>"Dog",2=>"Horse"); $a2=array(2=>"Bird", 0=>"Cat",4=>"Fish"); print_r(array_intersect_key($a1,$a2)); ?>

Output:

Array ( [0] => Cat [2] => Horse )

Example 2

"Cat",1=>"Dog",2=>"Horse"); $a2=array(2=>"Bird", 3=>"Rat",4=>"Fish"); $a3=array(2=>"Dog",6=>"Cow",7=>"Bird"); print_r(array_intersect_key ($a1,$a2,$a3)); ?>

Output:

Array ( [2] => Horse )