Concatenating Variable Names in C?

Question

Is it possible to concatenate variable names in C? Specifically, I have a struct that contains 6 similar variables in it called class1, class2, class3, etc.

I want to run through a for loop to assign each variable a value, but I can't see how to do it without somehow concatenating the variable name with the value of the for loop counter.

How else could I do this?

Answer 1

When you find yourself adding an integer suffix to variable names, think I should have used an array.

struct mystruct {
    int class[6];
};

int main(void) {
    struct mystruct s;
    int i;
    for (i = 0; i < 6; ++i) {
        s.class[i] = 1000 + i;
    }

    return 0;
}

Note: A C++ compiler will barf at this because of class. You will need to figure out a different name for that field if you plan to compile this code as C++.

Answer 2

There are dynamic languages where you can do this sort of thing - C is not one of these languages. I agree with Sinan - arrays or STL vectors are the way to go.

As a thought experiment - what would happen if you have 100,000 of these variables? Would you have 100,000 lines of code to initialise them?

Answer 3

The C preprocessor can concatenate symbols, but have you considered just using an array?