c - 这个 C 程序的平均值为零。这有什么问题吗？

Question

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

int main()
{
    {
        float test1Marks, test2Marks, test3Marks, averageMarks;
        averageMarks = (test1Marks + test2Marks + test3Marks) / 3;

        printf("Test 1 Marks:");
        scanf("%f", &test1Marks);

        printf("Test 2 Marks:");
        scanf("%f", &test2Marks);

        printf("Test 3 Marks:");
        scanf("%f", &test3Marks);

        printf("Average Marks of tests are:%f", averageMarks);

    }
    return 0;
}

一切都很好，但给出平均值的最终输出是错误的。但是，当我将值分配给其中两个变量并通过 scanf 语法输入第三个值时，它会给出平均值，否则不会。

Answer 1

移动averageMarks=(test1Marks+test2Marks+test3Marks)/3;在最后一个scanf之后但之前用于打印平均值的 print 语句!

int main()
{
    float test1Marks,test2Marks,test3Marks,averageMarks;

    printf("Test 1 Marks:");
    scanf("%f",&test1Marks);

    printf("Test 2 Marks:");
    scanf("%f",&test2Marks);

    printf("Test 3 Marks:");
    scanf("%f",&test3Marks);

    /* Now with determined test1Marks, test2Marks, and test3Marks
       values we can compute their average:
    */
    averageMarks=(test1Marks+test2Marks+test3Marks)/3;

    printf("Average Marks of tests are:%f",averageMarks);

    return 0;
}