PHP array_unshift () Modify array key considerations _php Tips

This article analyzes the Array_unshift () in PHP to modify array key considerations. Share to everyone for your reference, specific as follows:

As we all know, Array_unshift () is used to add elements to the beginning of an array, but today it suddenly turns out that if the key value of an array is a numeric type (or can be converted to a numeric type), Array_unshift () modifiesthe key of all elements that are numeric.

Instance:

$a =array (111=> "dddddddddddd", "112" =>array ("one" => "Orange", "two" => "Hhhhh"), "113" =>array ("one" = > "Orange", "two" => "Hhhhh"), "Oooo" => "JJJJJ");
Print_r ($a); echo "</br>";
Array_unshift ($a, "aaaaaaaaa");
Print_r ($a); echo "</br>";

Output results:

Array ([a] => dddddddddddd [112] => Array ([one] => Orange [two] => hhhhh) [113] => Array ([one] => ; Orange [two] => hhhhh) [oooo] => jjjjj)
Array ([0] => aaaaaaaaa [1] => dddddddddddd [2] => Array ([ One] => Orange [two] => hhhhh) [3] => Array ([one] => Orange [two] => hhhhh) [oooo] => JJJJJ)

See, Array_unshift () after the array key value has changed, the original 111 into 1, really pits! In the future, when you use Array_unshift (), you need to pay special attention to this!

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