我是否了解变量的工作原理，对吗？

Question

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你好。我对C ++和一般编程非常陌生。我试图通过玩弄一些我已经了解的小组件来建立自己的信心，直到我熟悉为止，然后再学习更多。但是我很沮丧，因为我似乎无法使这段简单的代码起作用。我希望任何阅读此书的人都能理解我正在尝试的尝试，并且可以告诉我哪里出了问题。谢谢，麻烦您了。

#include <iostream>

int main(int argc, const char * argv[]) {


    char computer[100];
    char something[100];



    double price;
    double price2;
    double total = (price + price2);
    double budget;
    if (budget < total){ double need = total - budget;}
    if (budget > total ){ double surplus = budget - total;}
    double perday = total / 365;
    double remain = budget - perday;
    int A;

    std::cout << "Please tell me, the 'name' of the new computer that you would like to buy.\n";
    std::cin >> computer;
    std::cout << " How much does this " << computer << " cost?\n";
    std::cin >> price;
    std::cout << "Cool! Now tell me something else you would like to buy.\n";
    std::cin >> something;
    std::cout << "How much does " << something << " cost?\n";
    std::cin >> price2;
    std::cout << "I need to know your technology budget:\n £";
    std::cin >> budget;


    if (budget >= total)
    {std::cout << "Wow you have enough cash to get both " << computer << " and " << something << "\n with a surplus budget of £" << surplus;}

    else (budget < total) {
    std::cout << "I am sorry you lack the necessary funds right now. \n";
    std::cout << "Would you like to hear a payment plan?\n 1 for yes / 2 for no \n";
    std::cin >> A;
    }

    if (A = 1) {
            std::cout << "If you wanted to buy both " << computer << " and " << something << " \n by this time next year, you could pay £" << perday << "each day from now\n ";
            std::cout << "If I take today's payment now, you will have £" << remain << "left of your budget";}
        else return 0;}
}

你好。我对C ++和一般编程非常陌生。我试图通过玩弄我已经了解的小组件来建立自己的信心，直到我像以前一样熟悉为止...

Answer 1

首先，在范围内声明变量是一个坏习惯，除非您计划仅在该范围内使用该变量。