What is Variable in PHP
Variables are used to store data/information like string of text, numbers, etc.
PHP variable does not declared before adding a value to it. PHP automatically converts the variable to the correct data type depending on it's value.
Declaring a variable it can be reused the code.
Variables are assigned with the ( = ) operator and the variable on the left side and the expression to be evaluated on the right.
All variables in PHP are denoted with a leading the dollar sign ( $ ).
Create PHP Variable
<?php $variable_name = value; ?>
The following example with output the sum of two variables :
<?php $a = 5; $b = 10; echo $a + $b; ?>
Variable names in PHP are case-sensitive it means $colour is not same as $CLOUR.
<?php $colour = "Red"; echo "My favorite colour is $str"; // below statement will give error echo "My favorite colour is $STR"; ?>
My favorite colour is Red
Notice: Undefined variable: STR