Variable declaration with `for' loop

[slippy]

The compiler complains about the last statement in the following block:

for ( int i = 0; i <= 10; i++ ) {

          String placeholder;

          // Desired value for `placeholder' on the ith iteration
          // is "ObjectRefi", where `i' is an integer that has been converted 
          // to a string and appended to "ObjectRef".
  
          placeholder = strcat("ObjectRef" , toString(index));

          // The compiler doesn't like this next statement:   

          SomeObjectRef placeholder = new SomeObjectRef();

}

Why? (No arrays allowed!)
Resolution?

[dwks]

You're re-declaring placeholder in that code.

strcat("ObjectRef" , toString(index));

I hope you don't actually do that, because string literals are supposed to be constant.

If you're going to make up code that demonstrates a point, try to ensure that it is correct.

But I know what you mean.

Probably the best way to do that is to use only one variable if possible. If that's not possible, you could use something linear -- for example, appending a name onto a list of other names.

You could also "unroll" the loop, e.g.,

for(int i = 0; i < 3; i ++) std::cout << i << std::endl;

->

std::cout << 0 << std::endl;
std::cout << 1 << std::endl;
std::cout << 2 << std::endl;

But these are just hacks to get around what should be implemented with arrays. I know no arrays are allowed, but that's just plain stupid.

You could always use a container instead of an array. Like a vector or something . . .

[Daved]

>> SomeObjectRef placeholder = new SomeObjectRef();
What are you trying to do? You can't generate variable names dynamically in C++.

[dwks]

What are you trying to do? You can't generate variable names dynamically in C++.

Standard C++, at any rate. Though you can sort of emulate it with a std::map.

[Daved]

>> Standard C++, at any rate.
You can do that in non-standard C++?

[dwks]

Kinda sorta. I was thinking of dlopen() and DLLs on Windows and that sort of thing. Not so much dynamic name generation as dynamic function name resolution.

And I'm sure that someone's created a weird "dynamic-name-C++" variation with support for that . . .