Question

I have a homework problem for my C++ class and the problem wants us to have the user input a wavelength and then output the correct type of radiation. The point to notice is that there are more Wave Name values than there are Wave Lengths.

My solution is listed below:

const double WAVE_LENGTH[] = { 1e-11, 1e-8, 4e-7, 7e-7, 1e-3, 1e-2 };
const char* WAVE_NAME[] = { "Gamma Rays", "X Rays", "Ultraviolet", "Visible Light", "Infrared", "Microwaves", "Radio Waves" };

double waveLength;

std::cout << "Enter a wavelength in decimal or scientific notation\nWavelength: ";
std::cin >> waveLength;

for (unsigned short i = 0U; i < 6U; ++i)
{
    if (waveLength < WAVE_LENGTH[i])
    {
        std::cout << "The type of radiation is " << WAVE_NAME[i] << std::endl;
        break;
    }
    if (i == 5U) // Last iteration
        std::cout << "The type of radiation is " << WAVE_NAME[i + 1] << std::endl;
}

My question is regarding my approach at solving the problem, specifically within the loop. I can’t seem to find a way to handle all the situations without creating two conditions inside the loop which seems like it is a poor design. I realize I could use a series of if/else if statements, but I figured a loop is cleaner. Is my approach the best way or is there a cleaner way of coding this?

Thanks!

Answer 1

I think you can simplify your loop to this:

unsigned short i;

for (i = 0U; i < 6U; ++i)
{
    if (waveLength < WAVE_LENGTH[i])
    {
        break;
    }
}
std::cout << "The type of radiation is " << WAVE_NAME[i] << std::endl;