我的代码有很多问题,并且有人尝试向我解释它,但我仍然无法理解我做错了什么......这一切在我的脑海中似乎都是正确的。据我了解,我的字符扫描不正确。我也有返回值的问题,并且我的“int * 与 int 的间接级别不同”。我该如何修复我的代码?我完全迷失了。
#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#define PAUSE system("pause")
#define CLS system("cls")
#define FLUSH flush()
// PROTOTYPE FUNCTIONS
void displayMenu();
void flush();
char getUserChoice();
int newSale(int *price, char *firstTime, char *veteran, char *student, char *lastDay);
int outputPrice(int carSales[], int *carsSold, int *avgCarPrice, int *totalRevenue);
// MAIN
main() {
int carSales[500] = { 0 };
int price = 0, avgCarPrice = 0, totalRevenue = 0, carsSold = 0;
char firstTime = 'n', veteran = 'n', student = 'n', lastDay = 'n';
char userSelection;
do {
userSelection = getUserChoice();
switch (userSelection) {
case 'A': // ENTER A NEW SALE
newSale(&price, &firstTime, &veteran, &student, &lastDay); // call function to ask questions
printf("\nPRICE OF CAR: %i\n", price);
carsSold++; // will add to +1 to the amount of cars sold
carSales[carsSold] = price; // add the car to carSales array
PAUSE;
break;
case 'B': // OUTPUT STATS
outputPrice(&carSales[500], &carsSold, &avgCarPrice, &totalRevenue);
PAUSE;
break;
case 'Q': // Quit Program
printf("Thanks....\n");
break;
default: // Invalid Selection
printf("Invalid selection...try again!\n");
PAUSE;
break;
} // end switch
} while (userSelection != 'Q');
PAUSE;
} // end of main
// DISPLAY THE MENU
void displayMenu() {
CLS;
printf("========== MAIN MENU ==========\n");
printf("A. ENTER NEW CAR\n");
printf("B. OUTPUT STATS\n");
printf("Q. QUIT\n");
printf("Enter your choice: ");
} // end displayMenu
// FLUSH
void flush() {
while (getchar() != '\n');
} // end flush
// GET THE USER CHOICE
char getUserChoice() {
char result;
displayMenu();
scanf("%c", &result); FLUSH;
result = toupper(result);
return result;
} // end getUserChoice
int newSale(int *price, char *firstTime, char *veteran, char *student, char *lastDay) {
// ASK QUESTIONS
printf("What is the sticker price of the car?\n");
scanf("%i", &price);
printf("Are you a first time buyer? (y/n)\n");
scanf("%s", firstTime);
printf("Are you a veteran? (y/n)\n");
scanf("%s", veteran);
printf("Are you a student (y/n)\n");
scanf("%s", student);
printf("Is it the last day of the month? (y/n)\n");
scanf("%s", lastDay);
// CALCULATE PRICES
if (*lastDay == 'y') { // car is discounted by 3% if user said yes
*price = *price - (((int)(*price) * 3) / 10); // (int) is added to keep the cocmpiler from complaining due to an implicit cast to floating point.
}
if (*firstTime == 'y') { // if it's the user's first time buying, $100 is given in credit
*price = *price - 100;
}
if (*student == 'y' && firstTime == 'y') { // car is discounted by $200 if user is a student and first time buyer- they also recieve the other discounts
*price = *price - ((int)(*price) - 200);
}
if (*veteran == 'y') { // veterans recieve 2% off the final price of the car
*price = *price - (((int)(*price) * 2) / 10);
}
return price;
}
int outputPrice(int carSales[ ], int *carsSold, int *avgCarPrice, int *totalRevenue) {
printf("The total cars sold is: %i", carsSold); // Display the amount of cars sold
for (int i = 0; i < 500; ++i) { // add all the prices in carSales
*totalRevenue = *totalRevenue + carSales[i];
}
printf("The Average car sold price: %i", avgCarPrice); // Display the avg price of the cars
printf("Total revenue: %i", totalRevenue); // Display total revenue
return;
}
最佳答案
首先,outputPrice
函数的返回类型应该是void
而不是int
;当我最初尝试编译您的代码时,这给了我一个错误。
接下来,在 newSale
函数中,该行
scanf("%i", &price);
应改为
scanf("%i", price);
因为price
已经是一个指针。在其他四个 scanf
调用中,%s
应更改为 `%c;例如
scanf("%s", firstTime);
应改为
scanf("%c", firstTime);
%s
是字符串的格式说明符; %c
用于字符。另请注意,参数仍然不需要通过在其名称前添加 &
来引用,因为它们也已经是指针。第三个 if
语句的第一行应更改为
if (*student == 'y' && firstTime == 'y') {
至
if (*student == 'y' && *firstTime == 'y') {
请注意 firstTime
前面的 &
。这是必要的,因为 firstTime
是一个指针,而不是字符,因此将其与字 rune 字 'y'
进行比较将产生不正确的结果结果。但是,firstTime 是指向字符的指针,因此使用 *
取消引用它会返回一个字符,然后可以将其与字 rune 字进行比较,而不会出现问题。 return语句也有问题:
return price;
应该是
return *price;
因为函数的返回类型是int
,而price是一个int
指针。
在 outputPrice
函数中,所有 printf
语句中的参数都需要取消引用。例如
printf("The total cars sold is: %i", carsSold);
应该是
printf("The total cars sold is: %i", *carsSold);
因为 carsSold
是一个 int
指针,而不是 int
本身。
此外,需要为 main
指定返回类型 int
以避免编译器警告。
关于c - scanf 格式字符串需要类型参数,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/48455657/