In this lesson, you will learn about using the $ single dollar sign and $$ double dollar sign in PHP and examples to understand the topic better.
A variable with a single dollar sign $ in PHP stores any value, including strings, integers, floats, and other data types.
On the other hand, The reference variable $$ (double dollar) stores the variable’s value inside it. To understand the difference better, let’s see an example.
Example
<!DOCTYPE html> <html> <body> <?PHP // Difference between $ and $$ $Variable = "Standard_Variable"; $$Variable = "This is a reference variable"; echo $Variable . "<br/>"; echo $$Variable . "<br/>"; echo $Standard_Variable; ?> </body> </html>
Output
Standard_Variable This is a reference variable This is a reference variable
The variable “Variable” has the value MyString_Variable in the above example. By assigning the value “This is a reference variable” to the reference variable $$Variable, we have printed the values $Variable, $$Variable, and $MyString_Variable.
This concludes the $ and $$ Variables lesson. In the next lesson, you will learn about another important keyword in PHP, the constants!