Variable is an identify which is use to identify data value from memory and its value can be changed at run time.
Rule of declaration of variable
- The first charater of variable name must be an alphabet.
- It’s never allow any special charater Like:(-,*,.)
- It’s allow under score (_)
- It’s does not allow any blank space.
- It’s allow digit but not at the begining.
Example in PHP
<?php $a=2; $str="string"; ?>