Array and hex values C++?

Question

I have a .txt with some numbers in hexadecimal and I put them into an array with ifstream . However, it doesn't print right, I mean, the numbers don't tally. This is my code:

void arrayNumbers(unsigned int longSize, unsigned int array[]) {
    file.open("hex.txt");
    int i;
    if(file){
        longSize=4; 
        array[longSize];
        for(int i=0;i<longSize;i++){ 
            file >> hex >> array[i];
            cout << array[i]<< endl; 
        }
        cout << "RIGHT" << endl;
    }
    else
        cout << "WRONG" << endl;

    file.close();
}

And in main() , I have:

void main() {
    unsigned int array[longSize];
    unsigned int longSize=4;
    arrayNumbers(longSize,array);
    cout << "OK" << endl;
}

What's happening here? TT

Answer 1

longSize=4; 
array[longSize];

This bit is completely wrong. Things you're trying to do here that you can't do:

• Increase the size of an array at runtime (presumably your intent with the meaningless array[longSize] )
• Choose the size of an array from a runtime value ( longSize )

Consider a std::vector instead.

Furthermore, your main returns void instead of int (which is ill-formed) and the array inside main has the size of yet another runtime variable, which is declared after the array!

Finally, I strongly recommend using a conventional indentation and brace-formatting style, as yours is strange and makes the code hard to read.

Answer 2

The error is probably that you don't pass hex to cout before you print the numbers.

If cleaned your program a little:

#include <iostream>
#include <fstream>

using namespace std;

void arrayNumbers(unsigned int longSize, unsigned int array[]) {
    fstream file("hex.txt");
    if (file){
        for (int i = 0; i < longSize; i++){
            file >> hex >> array[i];
            cout << hex << array[i] << endl;
        }
        cout << "RIGHT" << endl;
    } else {
        cout << "WRONG" << endl;
    }
}

void main() {
    const size_t longSize = 4;
    unsigned int array[longSize];

    arrayNumbers(longSize, array);
    cout << "OK" << endl;
}