《C语言》if语句（5）

#include <stdio.h>

int main()
{
    int a;
    a = 2;
    //第一种
    if(a == 2)
    {
        printf("a number is 2");
    }

    //第二种
    if(a == 2)
    {
        printf("a number is 2");
    }
    else
    {
        printf("a number not 2");
    }

    //第三种
    if(a == 2)
    {
        printf("a number is 2");
    }
    else if (a == 3)
    {
        printf("a number is 3");
    }
    else
    {
        printf("a number not is 2 or 3");
    }
    return 0;
}