Variable is used to store the value in php. Value can be string, numbers etc. Variable does not need to be declared before adding a value to it. PHP automatically converts the variable to the correct data type, according to value.
Declaring PHP Variable
In PHP, a variable starts with the $ sign, followed by the name of the variable.
<?php $text = "This is an variable example"; $a = 50; $b = 50.5; ?>
PHP Variable Declaration rules
PHP variables must start with letter or underscore only. A variable name cannot start with a number or any special symbols. Php variable name can contain only alpha-numeric characters and underscores. Variable names are case-sensitive for example $name and $NAME both are two different variables in PHP.