Variables introduction
Variables are used by programmers to store values and to refer to those values in code. Variables in PHP need not be defined. Variable types also do not exist although variable scope does. All variables begin with a $ sign. Variable names can contain numbers, letters and underscores. Variable names can only begin with letters or underscores. PHP variables are case sensitive. For ex: $a is different from $A. Below are given some examples of valid variable names:
