PHP Variables

Variable names given to location in the memory.These locations can contain integer,real or character contains.
Rules for variable names—-
A variable name is any combination of 1 to 26 alphabets, digits or underscores.

1. This first character in the variable name must be an alphabet or underscore.
2. Some valid variable names are:$ss, $s_s, $_1213 etc.
3. No commas or blanks are allowed within a variable name.

PHP lets you store numbers and text to those variables, as in these examples:
Example:-

 $pi = 3.1514444;
 $number_of_jupiters = 1;
 $name = "rahul kumar";
 $fish = "haddock";
 $pi,$number_of_jupiters,$name and $fish is PHP variable name.