将数字打印到可变小数位数

Question

我想在C中打印一个数字到可变数量的小数位。我已经编写了代码

#include<stdio.h>
main()
    {   int a;
        printf("Upto which number of decimal places you want to print value of '2.554648' ?");
        scanf("%d", &a);
        printf("Value of '2.554648 upto %d number of decimal places = %.af", a, 2.554648);
        return 0;
    }

Answer 1

在printf()使用*来标记您想要的小数位数：

#include <stdio.h>

int main(void)
{
    int a;

    printf("Upto which number of decimal places you want to print value of '2.554648' ?");
    scanf("%d", &a);
    printf("Value of '2.554648 upto %d number of decimal places = %.*f", a, a, 2.554648);

    return 0;
}

Answer 2

你需要*格式说明符。 这是一个简短的例子（参见ideone ）：

#include <stdio.h>

int main(void) {
    int a = 5;
    double temp = 5.0 / 7;
    printf("%.*f",a, temp);
    return 0;
}