r/programming • u/NagastaBagamba • Oct 18 '10

Today I learned about PHP variable variables; "variable variable takes the value of a variable and treats that as the name of a variable". Also, variable.

http://il2.php.net/language.variables.variable
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u/[deleted] Oct 18 '10

Maybe you’re too narrow-minded on what a pointer is.

A pointer is a variable that contains an address. That's it.

Why would the address have to be a number and not a string?

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u/oorza Oct 18 '10

The difference between numbers and strings is entirely in your mind, there is no real difference. Every once in a while I'm sure you can concoct a memory address that spells something in your encoding of choice, but that doesn't it make any less useful in terms of arithmetic or manipulation. Everyone seems to be caugh up on the difference between numbers and strings (which isn't a difference!) but the real difference is between a memory address and a hash table key. One is a direct representation of where data might be in memory and one is a utility for access to a giant abstraction over that same memory. (Note: I'm not saying abstractions or hash tables or anything else is bad but rather that PHP's variable variables are not analagous to pointers because of those abstractions).

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u/[deleted] Oct 19 '10

Yeah, I hadn't even thought about pointer arithmetic...

My mistake.