类型转换、运算符'

using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{

//while(true):死循环;

#region:收起来;

a++:先赋值在运算；

++a：先运算再赋值；

关系运算符：bool接受；

运算顺序：1）++；--     2）*；/；%；        3）+；—；       4>;<;>=;<=;       5)&&;||

(特殊：！；（）；)

7 的倍数：Console.WriteLine(num%7==0);

十位数是7：Console.WriteLine(num/10==7);

个位数是7：Console.WriteLine(num%10==7);

/*int a;
a = 1;
int b = 3;
int c = a + b;
Console.WriteLine(c);
Console.ReadLine(); */

/* Console.WriteLine("请输入变量a的值");
string a=Console.ReadLine ();
Console.WriteLine ("请输入变量b的值");
string b=Console.ReadLine();
Console.WriteLine ("a+b的和为：");
Console.WriteLine(a+b);

/*int a1=int.Parse (a);
int b1=int.Parse (b);
int c=a1+b1;
Console.WriteLine (c);
Console.ReadLine ();*/

/* Console.WriteLine("请输入a的变量");
string a = Console.ReadLine();
Console.WriteLine("请输入b的变量");
string b = Console.ReadLine();
Console.WriteLine("a+b的和为:");
Console.WriteLine(a+b);*/
/* Console.ReadLine();
int a1 = int.Parse(a);
int b1 = Convert.ToInt16(b);
int c = a1 + b1;
Console.WriteLine(c);*/

/*double a1 = double.Parse(a);
double b1 = Convert.Todouble16(b);
double c = a1 + b1;
Console.WriteLine(c);*/
/*int a1 = int.Parse(a);

int b1 = Convert.ToInt16(b);
int c = a1 - b1;
Console.WriteLine(c);*/
/*double a1 = double.Parse(a);
double b1 = Convert.Todouble16(b);
double c = a1 * b1;
Console.WriteLine(c);*/
/*int a, b;
a=6;
b = 2;
a = a - b;
Console.WriteLine(a);*/

/* int a=1;
int b = 2;
string s = a.ToString() + b.ToString();*/
/* double a =1;
int b = 3;
double c = a + b;*/
/* double a = 1.4;
int b = 4;
int c = (int)a + b;

Console.WriteLine(c);

Console.ReadLine();*/

/* Console.Write("请输入数字a：");
int a=int.Parse( Console.ReadLine());
Console.Write("请输入数字b：");
int b=int.Parse(Console.ReadLine());
/* int c = a + b;
Console.WriteLine("加法的结果是："+c);
c=a-b;
Console.WriteLine("减法的结果是："+c);
c=a*b;
Console.WriteLine("乘法的结果是："+c);
c=a/b;
Console.WriteLine("除法的结果是："+c);
c=a%b;
Console.WriteLine("取余的结果是："+c);*/

/*int c=a++;
int d=++a;
Console.WriteLine(c);
Console.WriteLine(d);
/* bool c = a < b;*/

/* Console.WriteLine (c);*/
/* Console.WriteLine("请输入整数a");
int a = int.Parse(Console.ReadLine());
Console.WriteLine("请输入整数b");
int b = int.Parse(Console.ReadLine());
int c = a + b;
Console.WriteLine("减法的结果为:"+a);
c = a - b;
Console.WriteLine("乘法的结果为:" + a);
c = a * b;
Console.WriteLine("除法的结果为:" + a);
c = a / b;
Console.WriteLine("取余的结果为:" + a);
c = a % b;
Console.ReadLine();*/
/*Console.WriteLine("请输入整数a");
int a = int.Parse(Console.ReadLine ());
Console.WriteLine("请输入整数b");
int b = int.Parse(Console.ReadLine ());
int c= a++;
int d = ++a;
Console.WriteLine(c);
Console.WriteLine (d);
Console.ReadLine();*/
/* Console.WriteLine("请输入整数a");
int a = int.Parse(Console.ReadLine ());
Console.WriteLine("请输入整数b");
int b = int.Parse(Console.ReadLine ());*/
/*bool c = a < b;
Console.WriteLine(c);
Console.ReadLine();*/
/*Console.WriteLine("请输入整数a");
int a = int.Parse(Console.ReadLine());
Console.WriteLine("请输入整数b");
int b = int.Parse(Console.ReadLine ());
bool c = a == b;
Console.WriteLine(c);
Console.ReadLine();*/
/*Console.WriteLine("请输入整数a");
int a = int.Parse(Console.ReadLine());
Console.WriteLine("请输入整数b");
int b = int.Parse(Console.ReadLine ());
int c = 15;
bool l = a > b && c > a;
Console.WriteLine(l);

Console.ReadLine();*/
/*Console.WriteLine("请输入整数a");
int a = int.Parse(Console.ReadLine());
Console.WriteLine("请输入整数b");
int b = int.Parse(Console.ReadLine());
int c = 8;
bool k = a < b != b < c;
Console.WriteLine(k);
Console.ReadLine();*/
 Console.WriteLine("请输入整数a");
int a = int.Parse(Console.ReadLine());
Console.WriteLine("请输入整数b");
int b = int.Parse(Console.ReadLine ());
int c=5;
bool k=!(a<b&&b<c);

 int c = 35;
bool k = a>b - c - a && c > b;

int c = 5;
int d = a - b + c * a++;
 a -= b + 3;
Console.WriteLine (a);
Console.ReadLine();

Console.WriteLine("请输入数字");

int a = int.Parse(Console.ReadLine());
string s = a>12 ?"这是时间下午"+(a-12):"这是上午时间"+a;
 string s = a > 60 ? "老年" : "青年" ;
Console.WriteLine("这个数是一个："+s);
Console.ReadLine();