Small problems with the intersection of PHP arrays array_intersect(), array_inter_key() and other functions_PHP tutorial

The problem of finding the intersection of two arrays can be achieved using array_intersect(), array_inersect_assoc, array_intersect_key. The array_intersect() function is to find the intersection of two numbers and return an array with common elements in the intersection (only the arrays are worth comparing), array_intersect_assoc The () function binds the key value and the value and compares the intersection part together. The array_intersect_key() function compares the key values ​​of the two arrays and returns the array of key value intersection.

However, some minor problems have also been encountered in practical applications, as follows:

Example:

"Red","azzzz1"=>"art","peak"=>158); $array1 = array("red"=>"Red2","greena" =>"red","Red15"=>"Red",7=>"Level","Width"=>"Red","azzzz"=>"art","peak"=> ; 158); echo "
"; $num = array_intersect_key($array,$array1); print_r ($num); ?>

Running result:

Array ( [red] => Red [Red15] => Red [7] => Level [Width] => Red [azzzz1] => art [peak] => 158 ) Array ( [Red15] => Red [7] => Level [Width] => Red [peak] => 158 ) Array ( [red] => Red [Red15] => Red [7 ] => Level [Width] => Red [peak] => 158 )

Summary:

　1. The array_intersect() function only compares array values, and if there is a comparison between "Red" and "Red2", it will return "Red", otherwise it will not return "Red2";

　2. The array_intersect_assoc() function compares the value of the array with the key value, and there will be no array_intersect situation, which is suitable for stricter comparisons;

　3. The array_intersect_key() function is suitable for comparing the intersection of two array key values. It returns not only the key value, but the key value and the corresponding array value.

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