Analysis of php array usage rules, php array rules_PHP tutorial

Analysis of php array usage rules, php array rules

This article analyzes the usage rules of arrays in PHP with examples. Share it with everyone for your reference. The specific analysis is as follows:

Arrays play a very important role in php. Values ​​such as strings, pictures, numbers, and videos all exist in the form of arrays, so it is necessary to understand the various rules of arrays.

1. Key, value.

Basic form of array:

array( [key =>]
value
   , ...
)

key=>value, where the key can only be two types, integer and string. The value can be in various forms. Except for numbers, other values ​​must be enclosed in strings with '' or "". The following example illustrates the rules:

<&#63;php  
$a = array(-1=>2,
         -2=>3,
   '01'=>'99.jpg',
            8,
           'a',
     'b'=>TRUE,
         NULL,
            "",
      1.2=>0.5,
        );
  
     print_r($a);
&#63;>

Output result: Array ( [-1] => 2 [-2] => 3 [01] => 99.jpg [0] => 8 [1] => 0.5 => 1 [2] => [3] => )

I hope this article will be helpful to everyone’s PHP programming design.