What is the Difference between $var and $$var?

Please some one explain the difference between $var and $$var

 

$var is just a variable with name var, $$var takes string from variable $var and finds variable of that name. Example will be better:

$var = 'fruit';
$$var = 5;
echo $fruit; // echoes 5

Is that clear?

 

$$var uses the value of the variable whose name is the value of $var. It allows you to have a "variable variable" - the program can create the variable name the same way it can create any other string. That's helpful in situations like $item1, $item2, etc. The program can set $var equal to "item" plus a number, then use the value in that variable by referencing $$var.

 

Say you have this.

<?php
$var = "chocolate";
$chocolate = "is yummy";

echo $$var;

?>

It will echo "is yummy"

 

$$ represents a variable variable. Here's how they work

$foo = 'bar';
$var = 'foo';

echo $var; // foo
echo $$var; //bar
echo $foo; //bar

You first assign the value of a variable, $var, to the name of another variable. When you set $var to a value, it will replace that variable name with the value of the variable you provide it.

$test = 'asdf';
$$test = 'I am changing asdf\'s value!';
echo $$test; // I am changing asdf's value!
echo $test; // asdf
echo $asdf; // I am changing asdf's value!

 

Thanks for your help. The above coding is easily understandable. It nice explanations.

Thanks.

 

It's pretty handy, you can even have variable-variable-variables like so: $$$var, if you wanna be crazy, that is.

 

finally at the end, It will be confusing and we will not be sure for what we created such a variable....$$$$var Pretty insane.
I Understand it in code wise, But, can some one give me some practical use. In what scenarios we will be using such variables??

 

$var is just a variable with name var, $$var takes string from variable $var and finds variable of that name. Example will be better:

$var = 'fruit';
$$var = 5;
echo $fruit; // echoes 5

this example is best

 

It is used when you need flexibile variable naming... In this case, it is not used much. More used is version with magic properties in objects...

 

I have never heard of such thing called as magical property. but was curious to know what it is all about and googled a bit.
Found this link very interesting... worth taking a look at it

http://forums.darklordpotter.net/showpost.php?p=426882&postcount=89

 

Official php doc will be better
http://www.php.net/manual/en/language.oop5.overloading.php#language.oop5.overloading.members