Differences between array_merge and array + array in php

Differences between array_merge and array + array in php

This article introduces how to merge arrays using array_merge and how to merge arrays with arrays. For more information, see. Note: In php, array_merge discards the key of the original number and retains the key in the string format to form a new array. Keys are not merged regardless of the key name, keys in string format are merged unless the key name and value are the same. But array + array is different. it only places the data in the previous array in the new array first, and then checks whether the second array has more than the first array, if there is more than one, it is only a number, but in this case it will be added. This is the difference between the two. Let's look at the following example: 'Aass', 'E' => 'adsdfs', 'asd '=> 'asdsdd', 'ddfg' => 'dssdf '); $ B = array ('D' => 'adddd', 'adsdfs', 'asdfsdddd', 'D' => 'aass '); $ d = $ a + $ B; $ e = array_merge ($ a, $ B); var_dump ($ d); var_dump ($ e);?> Output result: Array 'D' => string 'aass '(length = 4) 'E' => string 'adsdfs' (length = 6) 'asd '=> string 'asdsdd' (length = 6) 'ddfg' => string 'dssdf' (length = 5) 0 => string 'adsdfs' (length = 6) 1 => string 'asdfsdddddd' (length = 10) array 'D' => string 'aass '(length = 4) 'E' => string 'adsdfs' (length = 6) 'asd '=> string 'asdsdd' (length = 6) 'ddfg' => string 'dssdf' (length = 5) 0 => string 'adsdf' (length = 6) 1 => string 'asdfsdddddd' (length = 10)