We have learned in the last tutorial, about Variable and its scope in PHP. Now, we will discuss some examples of variables and Data Types in PHP. But before that, if you have not seen the previous posts How to install PHP & Variable & its Scope in PHP, Please have a look at that first, and then continue with this post.
PHP $ and $$ Variables
What is $ variable or $$ variable?
- The $var is a var variable created with single dollar is an ordinary variable, with the name var that stores any value like string, integer, float, etc.
- The $$var double dollar is a reference variable that stores the value of the $variable inside it.
It allows you to have “Variables variable”, i.e., The string stored in normal variable allow users to create variable whose name is dynamic
To better understand consider this simple example:-
<?php
$blog=”Tekraze”;
$$blog=”Rahul CHANANA”;
echo $blog.” “;
echo $$blog.” “;
echo $Tekraze;?>
OUTPUT:
Tekraze
Rahul CHANANA
Rahul CHANANA
In the above example,
- $blog is just a variable with string value=“Tekraze”.
- $$blog is reference variable . $$blog uses the value referenced by the variable $blog,
- echo $blog print the value: Tekraze
- echo $$blog print the value: Rahul CHANANA value of this $blog variable is act as reference of second variable $$blog.
- echo $Tekraze print the value : Rahul CHANANA, Here $Tekraze also act as reference variable.
Let’s take an another example now using $ ,$$ and $$$
<?php
$name=“Haryana”;${$name}=“Chandigarh”;
${${$name}}=“Hisar”;
echo $name. “<br>”;
echo ${$name}. “<br>”;
echo $Haryana. “<br>”;
echo ${${$name}}. “<br>”;
echo $Chandigarh. “<br>”;?>
OUTPUT:
Haryana
Chandigarh
Chandigarh
Hisar
Hisar
In the above example, we have assigned a value to the variable name Haryana. Value of reference variable ${$name} is assigned as Chandigarh and ${${$name}} as Hisar.
Now we have printed the values as $name, ${$name}, $Haryana, ${${$name}} and $Chandigarh.
So this is for today, in our next tutorial we will learn about Data Types in PHP. Stay connected with us for more tutorials.
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