Use B.I.F Of Php for Variables

first of all let you know what is B.I.F ? its just built in function of php ;) nothing new 

• strtolower()
• strtoupper()
• ucfirst()
• lcfirst()
• ucwords()

PHP Variables

assuming that familiar with programming concepts

In PHP you define a variable with the following form:

$variable_name = Value;

If you forget that dollar sign at the beginning, it will not work. This is a common mistake for new PHP programmers!

PHP supports a number of different variable types: integers, floating point numbers, strings and arrays. In many languages, it's essential to specify the variable type before using it: for example, a variable may need to be specified as type integer or type array. Give PHP credit for a little intelligence, though: it automatically determines variable type by the context in which it is being used! 

Important Note:Variable names in PHP are case sensitive, so $php is different from $Php or $PHP