PHP $ and $$ Variables
The $var (single dollar) is a normal variable with the name var that stores any value like string, integer, float, etc.
The $$var (double dollar) is a reference variable that stores the value of the $variable inside it.
To understand the difference better, let’s see some examples.
Example 1
Output:
In the above example, we have assigned a value to the variable x as abc. Value of reference variable $$x is assigned as 200.
Now we have printed the values $x, $$x and $abc.
Example2
Output:
In the above example, we have assigned a value to the variable x as U.P. Value of reference variable $$x is assigned as Lucknow.
Now we have printed the values $x, $$x and a string.
Example3
Output:
In the above example, we have assigned a value to the variable name Cat. Value of reference variable ${$name} is assigned as Dog and ${${$name}} as Monkey.
Now we have printed the values as $name, ${$name}, $Cat, ${${$name}} and $Dog.