c++ - std::cout 不输出任何内容

Question

我正在阅读 Stroustrup 的书，Programming Principles and Practice Using C++。我可以输入温度，但在控制台中没有得到 std::cout。我没有编译错误。

这是代码。

#include <iostream>
#include <vector> // I added this which is different from the book

void push_back(std::vector<double> temps, double value) { // I added this which is different from the book, maybe I don't need this but I found it doing a search
    temps.push_back(value);
}

int main() {
    std::vector<double> temps;

    double temp = 0;
    double sum = 0;
    double high_temp = 0;
    double low_temp = 0;

    std::cout << "Please enter some integers"<< '\n';  // I added this in for the prompt

    while (std::cin >> temp)
        temps.push_back(temp);

    for (int i = 0; i < temps.size(); ++i) {
        if (temps[i] > high_temp) high_temp = temps[i];
        if (temps[i] < low_temp) low_temp = temps[i];
        sum += temps[i];
    }
        std::cout << "High temperature: " << high_temp << std::endl;  // There is no output for this and the next two lines
        std::cout << "Low temperature: " << low_temp << std::endl;
        std::cout << "Average temperature: " << sum/temps.size() << std::endl;

    return 0;
}

标签： c++

Answer 1

您的代码的问题在于它一直在循环等待输入。我对其进行了一些更改，以询问要输入多少值，以便您检查输出是否实际工作。

#include <iostream>
#include <vector> // I added this which is different from the book

void push_back(std::vector<double> temps, double value) { // I added this which is different from the book, maybe I don't need this but I found it doing a search
    temps.push_back(value);
}

int main() {
    std::vector<double> temps;

    double temp = 0;
    double sum = 0;
    double high_temp = 0;
    double low_temp = 0;
    int ntemp;

    std::cout << "Enter the number of temperatures to input:";
    std::cin >> ntemp;

    std::cout << "Please enter " << ntemp << " doubles"<< '\n';  

    for (int i = 0; i < ntemp; ++i)
    { 
        std::cin >> temp;
        temps.push_back(temp);
    }

    for (int i = 0; i < temps.size(); ++i) {
        if (temps[i] > high_temp) high_temp = temps[i];
        if (temps[i] < low_temp) low_temp = temps[i];
        sum += temps[i];
    }
        std::cout << "High temperature: " << high_temp << std::endl;  // There is no output for this and the next two lines
        std::cout << "Low temperature: " << low_temp << std::endl;
        std::cout << "Average temperature: " << sum/temps.size() << std::endl;

    return 0;
}