printf在调用通过引用传递变量的函数时发出警告

So I have two functions, one function is passing by reference a variable and the other one is returning the result.

所以我有两个函数，一个函数通过引用传递一个变量，另一个函数返回结果。

void dailyMiles(int *totalMiles)
{

    int milesDriven, totalDays, totalPeople;

    peopleInVehicle(&totalPeople); //calling other function
    daysPerWeek(&totalDays); // calling other function

    printf("Enter the amount of miles driven per day: \n");
    scanf("%d", &milesDriven);


    *totalMiles = (milesDriven * totalDays * 52 / totalPeople) * 2;

    printf("Total miles saved: %d\n", totalMiles);

    return;
}

int outputMiles()
{
    int totalMiles;

    dailyMiles(&totalMiles);

    return totalMiles;
}

I'm having a hard time trying to figure out why it gives me this warning in the terminal:

我很难弄清楚为什么它会在终端给我这个警告：

main.c:38:36: warning: format specifies type 'int' but the argument has type
  'int *' [-Wformat]
    printf("Total miles saved: %d\n", totalMiles);
                               ~~     ^~~~~~~~~~

You are probably wondering why the dailyMiles function's datatype is void; well, I'm calling other functions that ask for users input so whenever I call it in my main, it asks for users input two times.

您可能想知道为什么dailyMiles函数的数据类型为void;好吧，我正在调用其他要求用户输入的函数，所以无论何时我在main中调用它，它都要求用户输入两次。

4 个解决方案

#1

You don't want to print the pointer itself (totalMiles), you want to print what it points to (*totalMiles).

您不想打印指针本身（totalMiles），您想要打印它指向的内容（* totalMiles）。

printf("Total miles saved: %d\n", *totalMiles);

#2

In function void dailyMiles(int *totalMiles)
at statement 10: printf("Total miles saved: %d\n", **totalMiles**);

在函数void dailyMiles（int * totalMiles）at语句10：printf（“保存的总里程数：％d \ n”，** totalMiles **）;

Instead of using totalMiles You should use *totalMiles because you created an integer type pointer. To access the data inside it you will have to use the asterisk operator that is *

而不是使用totalMiles您应该使用* totalMiles，因为您创建了一个整数类型指针。要访问其中的数据，您必须使用星号运算符*

For example:

例如：

int *totalMiles;
...
...
...
printf("Total miles saved: %d\n", *totalMiles);

#3

In the function totalMiles dailyMiles (int *totalMiles), totalMiles is a pointer to an integer. So, to print its values just add * in front of totalMiles as given below:

在函数totalMiles dailyMiles（int * totalMiles）中，totalMiles是一个指向整数的指针。因此，要打印其值，只需在totalMiles前添加*，如下所示：

void dailyMiles(int *totalMiles)
{

int milesDriven, totalDays, totalPeople;

peopleInVehicle(&totalPeople); //calling other function
daysPerWeek(&totalDays); // calling other function

printf("Enter the amount of miles driven per day: \n");
scanf("%d", &milesDriven);


*totalMiles = (milesDriven * totalDays * 52 / totalPeople) * 2;

printf("Total miles saved: %d\n", *totalMiles);

return;

}

Hope this helps you. If it isn't working kindly let me know.

希望这对你有所帮助。如果它不工作，请告诉我。

#4

You need to "dereference" your int* (pointer) to get an int.

你需要“取消引用”你的int *（指针）才能得到一个int。

#1