c - 在使用多个 scanf() 时，它会跳过其余的 scanf()

Question

当我为 scanf()

输入一个值时

它只是跳过紧随其后的第二个、第三个和任何其他 scanf()。

这是我的代码:

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main()
{
    float manyTest, gr1, gr2, gr3, gr4, gr5, gr6, gr7, gr8;
    manyTest = gr1 = gr2 = gr3 = gr4 = gr5 = gr6 = gr7 = gr8 = 0;

    printf("How many tests you wanna average? (Minimum 1 Maximum 8)\n");
    scanf(" %f", &manyTest);

    if (manyTest <= 0) {
        printf("The Minimum is 1!\n");    
    } else
    if (manyTest > 8) {
        printf("The Maximum is 8!\n");
    } else {
        if (manyTest = 1) {
            printf("Write down your grades on those tests:\n");
            scanf(" %f", &gr1);
        } else
        if (manyTest = 2) {
            printf("Write down your grades on those tests:\n");
            scanf(" %f", &gr1);
            scanf(" %f", &gr2);
        } else
        if (manyTest = 3) {
            printf("Write down your grades on those tests:\n");
            scanf(" %f", &gr1);
            scanf(" %f", &gr2);
            scanf(" %f", &gr3);    
        } else
        if (manyTest = 4) {
            printf("Write down your grades on those tests:\n");
            scanf(" %f", &gr1);
            scanf(" %f", &gr2);
            scanf(" %f", &gr2);
            scanf(" %f", &gr3);
            scanf(" %f", &gr4);
        } else
        if (manyTest = 5) {
            printf("Write down your grades on those tests:\n");
            scanf(" %f", &gr1);
            scanf(" %f", &gr2);
            scanf(" %f", &gr2);
            scanf(" %f", &gr3);
            scanf(" %f", &gr4);
            scanf(" %f", &gr5);
        } else
        if (manyTest = 6) {
            printf("Write down your grades on those tests:\n");
            scanf(" %f", &gr1);
            scanf(" %f", &gr2);
            scanf(" %f", &gr2);
            scanf(" %f", &gr3);
            scanf(" %f", &gr4);
            scanf(" %f", &gr5);
            scanf(" %f", &gr6);
        } else
        if (manyTest = 7) {
            printf("Write down your grades on those tests:\n");
            scanf(" %f", &gr1);
            scanf(" %f", &gr2);
            scanf(" %f", &gr2);
            scanf(" %f", &gr3);
            scanf(" %f", &gr4);
            scanf(" %f", &gr5);
            scanf(" %f", &gr6);
            scanf(" %f", &gr7);
        } else
        if (manyTest = 8) {
            printf("Write down your grades on those tests:\n");
            scanf(" %f", &gr1);
            scanf(" %f", &gr2);
            scanf(" %f", &gr2);
            scanf(" %f", &gr4);
            scanf(" %f", &gr5);
            scanf(" %f", &gr6);
            scanf(" %f", &gr7);
            scanf(" %f", &gr8);
        }
        float avg = (gr1 + gr2 + gr3 + gr4 + gr5 + gr6 + gr7 + gr8) / manyTest;
        printf("Your average grade is: %.2f\n", avg);
    }
    system("pause");
    return 0;
}

我的代码有什么问题，它跳过了 scanf() 的其余部分？我想让代码做的是询问他们想要平均多少次测试，然后取那个数字(1 到 8 之间)并对其进行测试，然后它应该平均成绩。

让我们说:

How many test...?
2
Write down your grades:
100
90
Your average grade is: 95.00

但是，它真正做的是:

How many test.....?
2
Write down your grades:
90
Your average is: 90.00

甚至不让它获取其他变量的信息。

Answer 1

实际上，在您的代码中，罪魁祸首不是 scanf，而是这些错误的 方程

else if (manyTest = 8) //WROOOOONNGGGG!! =( =( =( =(

改为使用双等号...

else if (manyTest == 8) //correct! =)

因为你真正想要的是比较