How PHP uses arrays

This article mainly introduces how to use the array of PHP, has a certain reference value, interested friends can refer to, I hope you can learn a lot after reading this article, the following let the editor take you to understand it.

The use of arrays

/ * * = > find the corresponding key value through the key name * add, delete, change, check * / / find: find the corresponding key value $arr1 = ['await,' baked, 'clocked,' d']; $arr2 = ['username' = >' Wang Zhao', 'sex' = >' male']; the value of echo 'subscript 2:', $arr1 [2], "\ n" / / the value with subscript 2: cecho 'user name:', $arr2 ['username'], "\ n"; / / user name: Wang Zhao $arr3 = [/ / two-digit search [' id'= > '1001', 'name'= >' Zhang San'], ['id'= >' 1002', 'name'= >' Li Si']; echo 'subscript 0' name:', $arr3 [0] ['name'], "\ n" / / add the name with a subscript of 0: Zhang San / / add $arr = ['a', 'baked,' c']; $arr [] ='d'; / / add the element without specifying the key name, the key name is the number $arr ['username'] =' Wang Zhao'; / / add the element, specify the key name, the key name is the string print_r ($arr) / Array ([0] = > a [1] = > b [2] = > c [3] = > d [username] = > Wang Zhao) / / modify $arr = ['axiao,' baked, 'cached,' username'= > 'Wang Zhao']; $arr ['username'] =' Zhang San'; echo $arr ['username'], "\ n"; / / delete unset ($arr [' username']); / / delete the key-value pair print_r ($arr) with the key name 'username' / Array ([0] = > a [1] = > b [2] = > c) unset ($arr [1]); print_r ($arr); / / Array ([0] = > a [2] = > c) unset ($arr); / / release array / / print_r ($arr) / / output error Notice: Undefined variable Thank you for reading this article carefully. I hope the article "how to use arrays in PHP" shared by the editor will be helpful to you. At the same time, I also hope you will support us and follow the industry information channel. More related knowledge is waiting for you to learn!