> > --- sourabh kulkarni <[EMAIL PROTECTED]> wrote:
> >> can anybody let me know what is $$ in php and where it is
> >> used?
> >>
> >> Thanks,
> >> Sourabh
> James Keeline wrote:
> > The $$ before a variable name indicates that it is a dynamic
> > variable. Specifically, the actual name of the variable
> > being referred to is the contents of another variable.
> >
> > A simple example of use is:
> >
> > $X = "banana";
> > ${$X} = "ice cream";
> > print ${$X}; // displays "ice cream"
> >
> > In this example, $X holds a word. The ${$X} or $$X takes the
> > content of $X and uses it as a variable name which can be set
> > or used in another expression such as print.
--- Skylinux <[EMAIL PROTECTED]> wrote:
> Now what's the difference between the above and this:
> $X = "banana";
> $X = "ice cream";
> echo($X); // displays "ice cream"
>
> --
> Skylinux
> Computer and Robotic Research
> http://www.network-technologies.org
In your example you have simply reassigned the variable $X with a new value.
In my example the variable $X holds the *name* of a variable. The $$X or ${$X}
takes the *name* of the variable which can be set as the program is running.
// variable name
$X = "banana";
${$X} = 123;
The second statement is equivalent to coding:
${"banana"} = 123;
or
$banana = 123;
It's a subtle concept, I'll admit. It can be difficult to grasp initially.
However, when you need it, few alternatives will work as well.
James
_____
James D. Keeline
http://www.Keeline.com http://www.Keeline.com/articles
http://Stratemeyer.org http://www.Keeline.com/TSCollection
http://www.ITeachPHP.com -- Free Computer Classes: Linux, PHP, etc.
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