PHP array Key Name usage tips

This article mainly introduces the PHP array key name tips summary, analysis of PHP array key names common use of skills, with a certain reference value, the need for friends can refer to the next

This article summarizes in detail the PHP array key name technique. Share to everyone for your reference. The specific analysis is as follows:

1, $arr [true] is equivalent to $arr [1]; $arr [false] is equivalent to $arr [0].

2. Make null the key name, equivalent to create or overwrite a $arr[null], can be accessed using $arr[null] or $arr[""].

3. When using a number with a decimal point as the key name, the key name automatically intercepts the integer part as the key name. As $arr[123.45]=5, you can get the key value using $arr[123.45] or $arr[123], and use a foreach traversal with $arr[123].

4, $arr []=5, the element is added after the array $arr.

Note: The data type of the key name in the array is an integer or string type