Question

我无法在多个函数之间传递不同的值。也就是说，我试图让两个函数接受用户输入，然后将这两个输入都传递给第三个函数，该函数计算这些输入的总和。然后，它将总数传递给另一个计算真实总数的函数。最后，在那之后，最后一个功能显示最终编号。我似乎无法弄清楚如何使多个函数通过。

# include <stdio.h>
# include <stdlib.h>

int carLength(int userInput) //Length
{
int length = 0;
do
{
    printf("\nPlease input the length of the area being carpeted:");
    scanf("%d", &userInput);
} while (length = 0);
length = userInput; //Essentially using this to store user input so i can 
use it later.
return length;
}

int carWidth(int userInput) //Width
{
int width = 0;
do
{
    printf("\nPlease input the width of the area being carpeted:");
    scanf("%d", &userInput);
} while (width = 0);
width = userInput; //Same as width
return width;
}

int carCalculate(int cost) //cost
{
int width = userInput;
int cost = (width * length) * 20;
return cost;
}

float cardiscount(float discount) //discount
{
float discount = cost - (cost * .1);
return discount;
}

float displaydisc(float discount) //discount
{
printf("\nThe total cost is: %f\n", discount);
return discount;
}

int main()
{
int length = 0;
int width = 0;
int cost = 0;
int discount = 0;
do {
    length = carLength;
} while (length == 0);
    do {
        width = carWidth;
    } while (carWidth == 0);
    do {
        cost = carCalculate;
    } while (cost == 0);
    do {
        discount = cardiscount;
    } while (discount == 0);
    do {
        displaydisc;
    } while (discount > 0);
    printf("\n Thank you for using this program!");

system("pause");
}

Answer 1

有一些问题，

赋予大多数汽车功能的参数没有用
未提供所需的参数（carCalculate）
= 0上有=（分配而不是相等性测试）的循环
变量未更改的情况下的循环
在没有main()的情况下调用(param)中的函数

此代码应该有效：

int carLength() // <== no need to provide length, it is returned
{
    int length;
    do
    {
        printf("\nPlease input the length of the area being carpeted:");
        scanf("%d", &length);
    } while (length == 0); // <== length is changed within the loop
    return length;
}

int carWidth() //Width
{
    int width = 0;
    do
    {
        printf("\nPlease input the width of the area being carpeted:");
        scanf("%d", &width);
    } while (width == 0);
    return width;
}

int carCalculate(int width, int length) // <== need to provide values
{
    int cost = (width * length) * 20;
    return cost;
}

float cardiscount(float cost) //discount
{
    float discount = cost - (cost * .1);
    return discount;
}

void displaydisc(float discount) //discount
{
    printf("\nThe total cost is: %f\n", discount);
}

int main()
{
    int length; // <== no need to set to 0, as their values
    int width;  //     are going to be initialized later
    int cost;
    int discount;

    length = carLength();

    width = carWidth();

    cost = carCalculate(width, length);

    discount = cardiscount((float)cost);

    displaydisc(discount);

    printf("\n Thank you for using this program!");

    system("pause");
}

您还可能要求输入函数填充一个值，该值以指针作为参数给出，例如

int carLength(int *length) {
    do {
        printf("\nPlease input the length of the area being carpeted:");
        scanf("%d", length);
    } while (*length == 0);
}

在main中调用的

int

carLength( &length );

Answer 2

您不进行任何函数调用。函数调用必须在函数名称后带有打开/关闭括号。

例如，这不是函数调用：

functionA;

...这是一个函数调用：

functionA();

在C中的多个函数之间传递不同的值？

2 个答案: