C语言学习（4）

条件判断

if-else

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

int main()
{
    int a, b;
    a = ;
    b = ;
    if (a > b)//切记括号不能再加 ；号
    {
        printf("a is bigger\n");
    }
    else{
        printf("b is bigger\n");
    }
    system("pause");
    return ;
}
           

switch

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

//输入一个月份， 输出该月份有多少天
int main()
{
    int mon;
    while (scanf("%d", &mon) != EOF)
    {
        switch (mon)
        {
        case :
        case :
        case : 
        case :
        case :
        case :
        case :printf("month %d is 31 days\n", mon); break;
        case :
        case :
        case :
        case :printf("month %d is 30 days\n", mon); break;
        case :printf("month %d is 28 days\n", mon); break;
        default:printf("month error\n");
        }
    }
    system("pause");
    return ;
}