PHP uses a custom method to implement array merging example, array example

PHP uses a custom method to implement array merging example, array example

This example describes how PHP uses a custom method to merge arrays. We will share this with you for your reference. The details are as follows:

PHP provides powerful array functions and provides two methods for Array merging: array_merge and array_merge_recursive.

However, for our ever-changing business, these built-in methods do not fully meet our requirements.

For example, I have encountered the problem of array merging. The requirement is as follows:

There are two-dimensional arrays. Most of these two arrays have the same health name, but some health names may not exist in another array, what I need to do now is copy all the values in the second array to the first array (condition: when the values of one of the two arrays are the same)

Obviously neither of the built-in Methods meets the requirements (both methods only copy the values in the second array to the first corresponding Jian)

$ar1 = array("color"=> array("favorite"=>"red","name"=>"test"));$ar2 = array("color"=> array("favorite"=>"green","code"=>"code"));print_r (array_merge ($ar1, $ar2));print_r(array_merge_recursive ($ar1, $ar2));

We can see that array_merge only copies the value of each second array to the first array. Obviously, array 1 is favorite. the name is overwritten by two codes of the array, while array_merge_recursive does not overwrite the same health name. But once the two arrays have the same health name, it creates a new array and adds the values of the two arrays to the new array.

The following is a custom implementation method:

/*** @ Author: HTL * @ Description: Copy all the values of $ ar2 to the corresponding values of $ ar1. * @ Return: $ ar1 */function array_more_merge ($ ar1, $ ar2, $ key_name) {if (! $ Ar1 |! Is_array ($ ar1) | count ($ ar1) <= 0 |! $ Ar2 |! Is_array ($ ar2) | count ($ ar2) <= 0 |! $ Key_name | strlen ($ key_name) <= 0) {return $ ar1;}/* you cannot use for loops, because if the index in the Array is not continuous, you may not be able to use for the correct loop, for example, $ a = Array (1 => Array ("id" => 1 ), 8 => Array ("id" => 2), 4 => Array ("id" => 4); the number of arrays is 3, so only [1] can be found. [8] [4] won't be processed in the loop, because $ I <= count ($ a) is not true <br> */for ($ I = 0; $ I <= count ($ a); $ I ++) {print_r ($ a [$ I]);} foreach ($ ar1 as $ I => $ items) {foreach ($ ar2 as $ key => $ item) {if ($ ar2 [$ key] [$ key_name] = $ ar1 [$ I] [$ key_name]) {$ keys = array_keys ($ ar2 [$ key]); foreach ($ keys as $ name) {$ ar1 [$ I] [$ name] = $ ar2 [$ key] [$ name] ;}}} return $ ar1 ;} $ ar1 = '{"1": {"cost": "1", "id": "1", "total_price": "5"}, "2 ": {"cost": "2", "id": "2", "total_price": "10"}, "4": {"cost": "4 ", "id": "4", "total_price": "20"} '; $ ar1 = json_decode ($ ar1, true); $ ar2 =' {"1 ": {"cost": "1", "id": "1", "total_price": "5"}, "2": {"cost": "20 ", "id": "2", "total_price": "100"}, "4": {"cost": "40", "id": "4 ", "total_price": "200"} '; $ ar2 = json_decode ($ ar2, true); echo "array_merge_recursive:"; print_r (array_merge_recursive ($ ar1, $ ar2 )); echo "array_merge:"; print_r (array_merge ($ ar1, $ ar2); echo "array_more_merge:"; print_r ($ this-> array_more_merge ($ ar1, $ ar2, "id"); die ();

Shows the running result: