Variable in PHP

Variable in PHP

Variable is an identifier which holds data or another one variable and whose value can be changed at the execution time of script. In PHP, a variable starts with the $ sign, followed by the name of the variable.

Syntax to declare variable in php

$variablename=value;  

<?php

$str="Hello world!";
$a=5;
$b=10.5;
echo "String is: $str <br/>";  
echo "Integer is: $x <br/>";  
echo "Float is: $y <br/>";  

?>

String is: Hello world!
Integer is: 5
Float is: 10.5 

Variable $str will hold the string value Hello world!, variable $x will hold the interger value 5 and variable $y will hold float value 10.5.

Rules to declare variable in PHP

• A variable starts with the $ sign, followed by the name of the variable
• A variable name must start with a letter or the underscore character
• A variable name can't start with a number.
• A variable name can only contain alpha-numeric characters and underscores (A-z, 0-9, and _ )
• Variable names are case-sensitive ($str and $STR both are two different)