我给 %f 的输入没有保存

Question

gradeOne和secondGrade不保存我给的数字。所以我不能得到平均值，因为，总是以 (0 + 0)/2 的除法结尾，有人可以帮助我吗？

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

    int main()
    {
    int students;
    char name[50];
    double gradeOne, secondGrade, classAverage = 0, average = 0;

    for(students = 1;students <= 15; students++){
        printf("Tell me Your name: \n");
        fflush(stdin);
        scanf("%[^\n]s", &name);
        //saves name
        printf("Tell me your first grade: \n");
        scanf("%f", &gradeOne);
        printf("Tell me your second grade: \n");
        scanf("%f", &secondGrade);
        //saves grade


        printf("\n========================================\n");

        printf("Student: %s\n", name);
        printf("First Grade: %3.2f \nSecond Grade: %3.2f \n", gradeOne, secondGrade);
        printf("%f", average);

        printf("\n========================================\n");

        average = (gradeOne + secondGrade)/2;
        //creates average
        printf("Average of the %d student: %3.2f",students, average);

        classAverage += average;
        //creates class average

    }
        classAverage = classAverage / (students - 1);
        printf("The class average was: %3.2f", classAverage);

    return 0;
}

Answer 1

scanf()中的

%f用于阅读float。您应该使用 %lf 来阅读 double。

请注意，您应该在 printf() 中使用 %f 进行打印 double。较新的规范允许 %lf 用于 printf()，但 %f 应该更好地兼容。

我给 %f 的输入没有保存

The input that i give to my %f does not save

c

math

average