The $ operator in PHP is used to declare a variable. In PHP, a variable starts with the $ sign followed by the name of the variable. For example, below is a string variable:
$var_name = "Hello World!";
The $var_name is a normal variable used to store a value. It can store any value like integer, float, char, string etc. On the other hand, the $$var_name is known as reference variable where $var_name is a normal variable. The $$var_name used to refer to the variable with the name as value of the variable $var_name.
Examples:
Input : $Hello = "Geeks for Geeks" $var = "Hello" echo $var echo $$var Output : Hello Geeks for Geeks Input : $GFG = "Welcome to GeeksforGeeks" $var = "GFG" echo $var echo $$var Output : GFG Welcome to GeeksforGeeks
Explanation: In the above example, $var stores the value “Hello”, so $$var will refer to the variable with name Hello i.e., $Hello.
Below program will illustrate the $ and $$ operator in PHP.
<?php // Variable declaration and initialization $var = "Hello" ;
$Hello = "GeeksforGeeks" ;
// Display the value of $var and $$var echo $var . "\n" ;
echo $ $var ;
echo "\n\n" ;
// Variable declaration and initialization $var = "GFG" ;
$GFG = "Welcome to GeeksforGeeks" ;
// Display the value of $var and $$var echo $var . "\n" ;
echo $ $var ;
?> |
Hello GeeksforGeeks GFG Welcome to GeeksforGeeks