7.18 学习笔记

while(执行条件){ 循环体 if（条件） break } 执行条件==0时循环结束 可以使用i++和i--对循环数进行限制

#include <stdio.h>
int main()
{
    int n;
    printf("输入月份: ");
    scanf("%d", &n);
    switch (n)
    {
    case 3:
        printf("春季\n");
        break;
    case 4:
        printf("春季\n");
        break;
    case 5:
        printf("春季\n");
        break;
    case 6:
        printf("夏季\n");
        break;
    case 7:
        printf("夏季\n");
        break;
    case 8:
        printf("夏季\n");
        break;
    case 9:
        printf("秋季\n");
        break;
    case 10:
        printf("秋季\n");
        break;
    case 11:
        printf("秋季\n");
        break;
    case 12:
        printf("冬季\n");
        break;
    case 1:
        printf("冬季\n");
        break;
    case 2:
        printf("冬季\n");
        break;
    default:
        printf("输入错误\n");
        break;
    }
    return 0;
}

#include <stdio.h>
int main()
{
    while (1)
    {
        printf("欢迎来到菜单\n");
        printf("1.加法\n");
        printf("2.减法\n");
        printf("3.乘法\n");
        printf("4.除法\n");
        printf("5.退出\n");
        printf("请输入你的选择：");
        int choice;
        scanf("%d", &choice);
        
            if (choice == 1){
                printf("加法\n");
        }
        else if (choice == 2)
        {
            printf("减法\n");
        }
        else if (choice == 3)
        {
            printf("乘法\n");
        }
        else if (choice == 4)
        {
            printf("除法\n");
        }
        else if (choice == 5)
        {
            printf("退出\n");
            break;
        }
        else
        {
            printf("输入错误\n");
            break;
        }
    }
}

#include <stdio.h>
int main()
{
    int i = 1;
    while (i <= 10)
    {
        printf("%d\n",i++);
    }
    return 0;
}

#include <stdio.h>
int main()
{
    int i = 1;
    while (1)
    {
        printf("欢迎来到菜单\n");
        printf("1.加法\n");
        printf("2.减法\n");
        printf("3.乘法\n");
        printf("4.除法\n");
        printf("5.退出\n");
        printf("请输入你的选择：");
        int choice;
        scanf("%d", &choice);
        if (i == 3)
        {
            break;
        }
        if (choice == 1)
        {
            printf("加法\n");
            i++;
        }
        else if (choice == 2)
        {
            printf("减法\n");
            i++;
        }
        else if (choice == 3)
        {
            printf("乘法\n");
            i++;
        }
        else if (choice == 4)
        {
            printf("除法\n");
            i++;
        }
        else if (choice == 5)
        {
            printf("退出\n");
            break;
        }
        else
        {
            printf("输入错误\n");
            break;
        }
    }
    return 0;
}

#include <stdio.h>
int main()
{
    int i = 15;
    while (i <= 100)
    {
        if (i % 3 == 0 && i % 5 == 0){
            printf("%d\n", i);
        }
        i++;
    }
    return 0;
}