[harlock]

I'd like to figure out how to construct the name of a variable using two or more variable names.

lets say $variable1 = whee
and $variable 2 = fun

I'd like to construct a variable variable named "$wheefun"

If I try something like:

Code:

<?php

$variable1 = 'whee';
$variable2 = 'fun';

$$variable1.$variable2 = foo;

echo $wheefun;

?>

I do not get 'foo' from $wheefun, I get nothing. I don't think I have the right syntax, if it's possible at all. Not sure if the period separator works on the left side of a statement like that.

What I am doing is making a function where we build the variable name from two different variables, assign it a value from a third variable, and then using GLOBAL to make it global when I'm done. I'm doing this to take some existing variables and appending a suffix onto their name, and the suffix is determined by another variable.

There's another way I can get around it, but the cleanest, most elegant solution would involve assembling a variable name from multiple variables.

--Mike

[Sabu]

Not that I ever support this function, but if you really needed to, look into something like this

PHP Code:

eval("\${$variable1}{$variable2} = foo"); 

[harlock]

Not that I ever support this function,

Why would you not support the use of that function? Is it bad in some way? (perhaps you are trying to tell me that I should never be in a situation where I have to use it in the first place?

[Sabu]

A small quote from the creator of PHP:

If eval() is the answer, you're almost certainly asking the wrong question.

Especially if you're using a form of user input to get the values of $variable1 and $variable1, someone could play around with the values and potentially cause harm to your server. What if I filled in your form so that the value of $variable2 is

Code:

meh = 0; unlink($PHP_SELF); \$$variable1.$variable2

Place that in the above code and tell me what happens.

[harlock]

Especially if you're using a form of user input to get the values of $variable1 and $variable1, someone could play around with the values and potentially cause harm to your server.

Right. Fortunately neither of the variables comes from user input. I'm probably going about it the wrong way, but it'd be used to generate an error flag for an option in a list of options being generated from a MySQL database. For example, If a user made a mistake when working on an entry related to foo1, it'd generate a value of 1 in a variable called $foo1error. This would be called up in multiple places, first for some error output the top of the page, and later down below in the regenerated form. I realize there are other ways of doing this and so far have avoided using eval. I just thought of it as an easy way to deal with it, but dynamic creation of variable names seems to crop up all sorts of security issues.

[Sabu]

You're far better off using arrays for that, use $errorarray[errorid] and check for the value of that.

[dennispopel]

Hello,

No need for eval().
$myFreakyVar = $var1 . $var2;
$x = &$$myFreakyVar;
$x = 'foo';

[Sabu]

Dennis

The point was to dynamically create the variable 'myFreakyVar' without at first knowing what it is to be called.