c - 如何避免在每次调用函数后将变量重新初始化为 0？

Question

我有以下用 C 语言编写的程序。为简单起见，下面显示的代码片段中省略了预处理器指令。

int entry(int people){    //function to add people to the event
    int entered;
    printf("Please enter the number of people you wish to add to the list.");
    scanf("%d", &entered);
    int newpeople = people + entered;
    return newpeople;
}

int left(int people){
    printf("How many people have left?");
    int left;
    scanf("%d", &left);
    int newpeople = people - left;
    return newpeople;
}

int main(void){
    int people = 0;    //to initialise the people variable
    while (1){
        int choice;
        printf("Choose between 1. New people enter or 2. People exit");
        scanf("%d", &choice);
        if (choice == 1){
            printf("You chose to add people.");
            printf("The new amount of people is: %d", entry(people));
        }
        else if (choice == 2){
            printf("You chose to remove people.");
            printf("The new amount of people is: %d", left(people));
        }
    }
    return 0;
}

我对这个程序的问题是，每当 while(1){} 循环初始化时，它都会删除先前由被调用函数返回的值。我希望它继续运行(即向我显示菜单)，直到我选择手动终止它。理想情况下，它应该将变量“int people”的值从循环的一个实例传递到下一个实例。

我发现 people 的值必须在 main 的某个地方初始化(否则其中会出现垃圾值)，但我在整个代码的多个地方尝试过这个，但没有成功。它只是每次都重新初始化为值 0。

任何帮助将不胜感激，即使它是正确方向的提示。

Answer 1

您应该重新分配人员，而不是在打印值时调用函数。

改变这个:

printf("The new amount of people is: %d\n", entry(people));

为此:

people = entry(people);
printf("The new amount of people is: %d\n", people);