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PHP $ and $$
PHP $ and $$ for beginners and professionals with examples, php file, php session, php date, php array, php form, functions, time, xml, ajax, php mysql, regex, string, oop
PHP $ and $$ VariablesThe $var (single dollar) is a normal variable with the name var that stores any value like string, integer, float, etc. The $$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<?php $x = "abc"; $$x = 200; echo $x."<br/>"; echo $$x."<br/>"; echo $abc; ?> 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<?php $x="U.P"; $$x="Lucknow"; echo $x. "<br>"; echo $$x. "<br>"; echo "Capital of $x is " . $$x; ?> Output: 
In the above example, we have assigned a value to the variable x as U.P. Value of reference variable $$x is assigned as Lucknow. Now we have printed the values $x, $$x and a string. Example3
<?php
$name="Cat";
${$name}="Dog";
${${$name}}="Monkey";
echo $name. "<br>";
echo ${$name}. "<br>";
echo $Cat. "<br>";
echo ${${$name}}. "<br>";
echo $Dog. "<br>";
?>
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.
Next TopicPHP Constants
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