C vs PHP – Pointers in C vs No Pointers in PHP

cPHPpointers

Both languages have the same syntax.

Why does C have the weird * character that denotes pointers (which is some kind of memory address of the variable contents?), when PHP doesn't have it and you can do pretty much the same things in PHP that you can do in C, without pointers? I guess the PHP compiler handles this internally, why doesn't C do the same?

Doesn't this add unneeded complexity in C? For example I don't understand them 🙂

Best Answer

Like so many things, the answer is of the form "Because X and Y are different things with different purposes".

In this case, the designers of both languages assumed that the users of their languages had a very different set of goals. For C, the primary use case was "portable assembly language", which really means getting down into the nitty-gritty of how the computer is actually managing its resources. There's no practical way to avoid memory address manipulation at the lowest level of abstraction, and so C has robust support for it.

PHP was intended to make dynamic web page content as flexible and painless as possible. This is quite a few steps removed from the super-low level of the C world; managing memory is, for the purposes PHP is intended to address, much too low level to be of much interest. Any kind of automatic memory management would be fine, so long as it is robust and reliable, and stays out of the way. That's exactly the situation you see in PHP; objects are allocated automatically, when needed, and garbage collected when they are no longer useable, and it all happens without the intervention of the PHP programmer.

It's perhaps of some interest to observe that PHP is itself written in C! the nitty gritty of memory management is written in C, which provides the tools needed to do that kind of thing, so that the language created, doesn't require the programmer to do much themselves.

Related Solutions

C Programming – Purpose of Arrays When Pointers Could Do the Job

Arrays are contiguous memory created on the stack. You can't guarantee contiguous stack memory without this syntactic sugar, and even if you could, you'd have to allocate a separate pointer in order to be able to do the pointer arithmetic (unless you wanted to do *(&foo + x), which I'm not sure but it might violate l-value semantics, but is at least quite awkward, and would scream out for some kind of syntactic sugar). Design-wise, it also is a form of encapsulation, since you can refer to the collection with a single identifier (which would otherwise require a separate pointer). And even if you could allocate them contiguously and allocated a separate pointer to reference them, you'd have either int fooForSomething, fooForSomethingElse... which forces a fair amount of creativity as your collection grows, so you might think to simplify with int foo1, foo2 ..., which looks just like an array but is harder to maintain.

Best Way to Have a Pointer to Several Methods in C++ – Code Critique

what is the best syntax and coding style for generating a pointer to a method?

Don't. Use std::function<void()>.

Now, on to the steps. Step 1 is technically illegal, but your compiler allowed it by implicitly taking the address for you. Step 2 is how it should be done. The name of a static function (in this case, Foo::dummy) is a function lvalue and must have it's address taken to be legal C++ and yield a function pointer.

Step 3 simply doesn't make any sense at all. You're trying to assign ... a run-time function pointer ... to a type? That makes no sense whatsoever. And then you try to access ... a member ... of a function pointer? Does not compute.

There are two parts to the answer "What do I do when I want to X in C++?". The first part, for C veterans only, is "Forget whatever you think you learned in C". The second part is about doing X.

how can i write an array of pointers or a pointer to pointers structure to store methods ( static or non-static from real objects )

std::vector<std::function<void()>> arr;

le done.

Best Answer

Related Solutions

C Programming – Purpose of Arrays When Pointers Could Do the Job

Best Way to Have a Pointer to Several Methods in C++ – Code Critique

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