Time = distance over speed in C

Question

I'm trying to find the time taken to travel over an inputted distance going at a constant speed in C. The code I have functions but the output is printed as 0? Any idea what is going wrong?

#include <stdio.h>
#include <stdlib.h>
int main() {
    int distance, speed = 80;
    float time;

    // This is how to read an int value
    printf("Please enter a distance in kilometers to be covered at 80KPH. \n");
    scanf("%d", & distance);
    printf("You typed: %d\n", distance);
    printf("\n");
    time = distance / speed;
    printf("It will take you %.2f to cover ", time);
}

Answer 1

因为两个操作数是整数,所以编译器生成整数除法的代码.但你想要真正的分裂.因此,将一个或多个操作数强制转换为浮点类型,编译器将发出实际除法的代码.

time = (float) distance / time;

整数分工是你在小学学到的.因此,例如,11/3是3余数2.在C中,表达式11/3的计算结果为3.这是整数除法.在你的情况下,似乎分子(距离)小于分母(时间),因此表达式

distance / time

评估为0.

这是由除法运算符的超载引起的常见混淆.如果两个操作数都是整数,则此运算符表示整数除法,否则为实数除法.

要学习的关键点是,操作数的类型决定了是使用整数还是实数除法.存储结果的变量类型对此选择没有影响.