PHP Variables

Variables are temporary storage containers. In PHP, a variable can contain any type of data, such as, for example, strings, integers, floating-point numbers, objects and arrays. PHP is loosely typed, meaning that it will implicitly change the type of a variable as needed, depending on the operation being performed on its value. This contrasts with strongly typed languages, like C and Java,where variables can only contain one type of data throughout their existence.

PHP variables are identified by a dollar sign $, followed by an identifier name. Variables must be named using only letters (a-z, A-Z), numbers and the underscore character; their namesmust start with either a letter or an underscore, and are one of only two identifier types in PHP that are case-sensitive (the other is constants, discussed below). Here are a few examples:

* $name = 'valid'; // Valid name

* $_name = 'valid'; // Valid name

* $1name = 'invalid'; // Invalid name, starts with a number

Variable of Variables
In PHP, it is also possible to create so-called variable variables. That is a variable whose name is contained in another variable. For example:

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