在main函数中使用类中的数组

Question

Consider the following code:

#include <iostream>
#include <string>
#include <algorithm>

int main()
{
    class treasure
    {
    public:
        char name[100];
        double value[100];
        double weight[100];
    };

    int itemNumber, totalWeight, i;

    treasure item;

    std::cout << "Enter total item weight: " << std::endl;
    std::cin >> totalWeight;
    std::cout << "Enter total item number: " << std::endl;
    std::cin >> itemNumber;
    for( i = 0; i < itemNumber; i++)
    {
        std::cout << "Enter item name: " << std::endl;
        std::cin >> item.name[i];
    }

    return 0;
}

I wanted to input 5 item in the array but it is just asking for two item. It takes one item at first and then after printing three lines again takes another input. What seems to be the problem. What did went wrong?

Answer 1

char name[100]; means that you can save up to 100 items of type char , not 100 strings.

An important effect here is that your input is buffered. std::cin >> item.name[i]; takes one char from the input buffer and writes it to name[i] . The rest of your input remains in the buffer and will be used for the next execution of cin , ie the next execution of the same code line.

So if you enter eg 'abc' it saves 'a' to item.name[0] , 'b' to item.name[1] and 'c' to item.name[2] . For item.name[3] the input buffer is empty so it waits for your next input.