c - 如何在用户定义的函数中避免重复

Question

编译后，我的 GetInt 函数导致函数内的 printf 语句在屏幕上打印 3 次。我相信这是在我将所有半径、底数和高度初始化为 GetInt(void) 时引起的，但我看不到其他方法可以准确地初始化这些变量。请帮忙!

#define _CRT_SECURE_NO_WARNINGS
#define PI 3.14159
#include <stdio.h>
#include <math.h>

int GetInt(void);
double CalcTriangleArea(int base, int height);
double CalcCircleArea(int radius);

int main(void)
{
    int radius, base, height;
    double triangleArea;
    double circleArea;

    radius = GetInt();
    base = GetInt();
    height = GetInt();
    triangleArea = CalcTriangleArea(base, height);
    circleArea = CalcCircleArea(radius);

    return(0);
}

int GetInt(void)
{
    int x;

    {
        printf("Please enter a radius: \n\n");
        scanf("%d", &x);

        printf("Please enter a base: \n\n");
        scanf("%d", &x);

        printf("Please enter a height: \n\n");
        scanf("%d", &x);
    }
    return(x);
}

double CalcTriangleArea(int base, int height)
{
    double triangleArea;
    printf("Triangle area is %.2f \n\n", triangleArea = .5*base*height);

    return(0);
}

double CalcCircleArea(int radius)
{
    double circleArea;
    printf("Area is %.4f \n\n", radius, circleArea = PI * pow(radius, 2));

    return(0);
}

Answer 1

一个经验法则是尽可能避免重复自己，也不要重复自己。假设您想将两行 (\n\n) 更改为三行 (\n\n\n)？您需要进行三次更改。

查看 GetInt 的基本结构，您正在打印一个提示符、两个新行、获取一个值并返回它。因此，我们可以这样编写新函数:

void getInt(char* prompt)
{
    int x, numberOfConversions;               // numConversions is the number of int's read from the keyboard buffer

    printf("%s: \n\n", prompt);
    numberOfConversions = scanf("%d", &x);

    while (numberOfConversions != 1)          // while the user did not enter a number
    {
        printf("Please enter a number: ");
        numberOfConversions = scanf("%d", &x)"
    }

    return x;                                 // Always returns a valid number
}