C++ if/else if语句不起作用

Question

我是C++的新手,我必须制作一个C++程序,使用传递引用对3个数字(最小 - 最大)进行排序.一切正常,直到我的函数中的if语句.我试图做很多调试,似乎每当我使用"<"时语句都不会执行.如果我这样做(n1 > n2),语句就会执行.如果有人能提供帮助,那就太棒了.这是我的代码:

#include <cstdlib>
#include <iostream>
#include <stdio.h>

using namespace std;

int sortNum(double &n1, double &n2, double &n3);

int main(int argc, char *argv[]) {
    double num1, num2, num3;

    printf("Welcome to Taylor's Sorting Program \n");
    printf("Enter 3 numbers and the program will sort them \n");
    printf("Number 1: \n");
    scanf("%d", &num1);
    printf("Number 2: \n");
    scanf("%d", &num2);
    printf("Number 3: \n");
    scanf("%d", &num3);

    sortNum(num1, num2, num3);

    printf("Sorted Values \n");
    printf("Number 1: %d ", num1);
    printf("\t Number 2: %d ", num2);
    printf("\t Number 3: %d \n", num3);

    system("PAUSE");
    return EXIT_SUCCESS;
}

int sortNum(double &num1, double &num2, double &num3) {
    double n1, n2, n3;
    n1 = num1;
    n2 = num2;
    n3 = num3;


    if (n1 < n2 && n1 > n3) {
        num1 = n2;
        num2 = n1;
        num3 = n3;
    } else if (n2 < n1 && n2 > n3) {
        num1 = n3;
        num2 = n2;
        num3 = n1;
    } else if (n3 < n2 && n3 > n1) {
        num1 = n2;
        num2 = n3;
        num3 = n1;
    }
    return 0;
}

Answer 1

您正在使用错误的格式说明符scanf().而不是%d(表示指向整数的指针),使用%lf(指向a的指针double).或者,在代码中更改double为int.

请注意,您的printf()发言从类似问题的困扰,而应该使用两种%f, %g或%e.