#include <stdio.h>
main()
{
double num1, num2, result;
printf("请输入num1:");
scanf("%lf", &num1);
printf("请输入num2:");
scanf("%lf", &num2);
result = num1 * num2;
printf("%.2lf * %.2lf = %.2lf\n", num1, num2, result);
}
备注:
.2
表示保留两位小数lf
表示接受double类型num,是一个声明的变量
以上都是给num加1,后面具体说说num1++
与++num1
的区别
备注:
num += a,等于, num = num + a -----------------(a可以是任意数字变量)
5 && 4, 为true
5 && 0, 为false
0 && 0, 为false
0 && 5, 为false
5 || 0, 为true
5 || 7, 为true
0 || 0, 为false
#include <stdio.h>
int main()
{
int numA, numB, minNum;
printf("请输入numA:");
scanf("%d", &numA);
printf("请输入numB:");
scanf("%d", &numB);
if (numA > numB)
{
minNum = numB; //numB为小
}
else//numA <= numB
{
minNum = numA;
}
printf("最小数为:%d\n", minNum);
return 0;
}
编写一个循环结构的程序,求数列前20项之和: 2/1,3/2,4/3,5/4,......,20/19,21/20
#include <stdio.h>
int main()
{
float sum = 0;
for (int i = 1; i <= 20; ++i)
{
sum += (i + 1) / i;
}
printf("前二十项和是:%f\n", sum);
return 0;
}
备注: