b3=num2<=num1;
Console.WriteLine(b);
Console.WriteLine(b1);
Console.WriteLine(b2);
Console.WriteLine(b3);
System.Console.Readline();
}
}
}
逻辑运算符
1.&&运算符
usingSystem;
usingSystem.Collections.Generic;
usingSystem.Linq;
usingSystem.Text;
namespaceCh5Demo16
{
classProgram
{
staticvoidMain(string[]args)
{
intnum1,num2;
strings1,s2;
boolb1,b2,b3;
num1=3;
num2=6;
s1="Hello";
s2="boy";
b1=num2>num1;
b2=s2==s1;
b3=b1&b2;
Console.WriteLine(b1);
Console.WriteLine(b2);
Console.WriteLine(b3);
System.Console.Readline();
}
}
}
2.||运算符
usingSystem;
usingSystem.Collections.Generic;
usingSystem.Linq;
usingSystem.Text;
namespaceCh5Demo19
{
classProgram
{
staticvoidMain(string[]args)
{
intnum1,num2;
strings1,s2;
boolb1,b2,b3;
num1=3;
num2=6;
s1="Hello";
s2="boy";
b1=num2>num1;
b2=s2==s1;
b3=b1||b2;
Console.WriteLine(b1);
Console.WriteLine(b2);
Console.WriteLine(b3);
System.Console.Readline();
}
}
}
3.!
运算符
usingSystem;
usingSystem.Collections.Generic;
usingSystem.Linq;
usingSystem.Text;
namespaceCh5Demo19
{
classProgram
{
staticvoidMain(string[]args)
{
strings1,s2;
boolb1,b2;
s1="Hello";
s2="boy";
b2=s2==s1;
b2=!
b1;
Console.WriteLine(b1);
Console.WriteLine(b2);
System.Console.Readline();
}
}
}
赋值运算符
usingSystem;
usingSystem.Collections.Generic;
usingSystem.Linq;
usingSystem.Text;
namespaceCh5Demo19
{
classProgram
{
staticvoidMain(string[]args)
{
strings1,s2;
s1="Hello";
s2="boy";
Console.WriteLine(s1);
Console.WriteLine(s2);
System.Console.Readline();
}
}
}
三元运算符
usingSystem;
usingSystem.Collections.Generic;
usingSystem.Linq;
usingSystem.Text;
namespaceCh5Demo19
{
classProgram
{
staticvoidMain(string[]args)
{
intnum1,num2,max;
num1=3;
num2=6;
max=num1>num2?
num1:
num2;
Console.WriteLine(max);
System.Console.Readline();
}
}
}
其他运算符
1.点运算符
System.Console.WriteLine("helloboy");
System.Console.RedLine();
2.索引运算符
usingSystem;
usingSystem.Collections.Generic;
usingSystem.Linq;
usingSystem.Text;
namespaceCh5Demo24
{
classProgram
{
staticvoidMain(string[]args)
{
intsum=0;
int[]num=newint[10];
for(inti=0;i<10;i++)
num[i]=i;
for(inti=0;i<10;i++)
sum+=num[i];
Console.WriteLine(sum);
System.Console.Readline();
}
}
}
4.check和uncheck运算符
usingSystem;
usingSystem.Collections.Generic;
usingSystem.Linq;
usingSystem.Text;
namespaceCh5Demo25
{
classProgram
{
staticvoidMain(string[]args)
{
byteb=255;
checked
{
b++;
}
Console.WriteLine(b.ToString());
System.Console.Readline();
}
}
}
Sizeof运算符
usingSystem;
usingSystem.Collections.Generic;
usingSystem.Linq;
usingSystem.Text;
namespaceCh5Demo25
{
classProgram
{
staticvoidMain(string[]args)
{
Console.WriteLine(Sizeof(byte));
Console.WriteLine(Sizeof(int));
Console.WriteLine(Sizeof(double));
System.Console.Readline();
}
}
}
6.typeof运算符
usingSystem;
usingSystem.Collections.Generic;
usingSystem.Linq;
usingSystem.Text;
namespaceCh5Demo25
{
classProgram
{
staticvoidMain(string[]args)
{
Console.WriteLine(typeof(byte));
Console.WriteLine(typeof(int));
Console.WriteLine(typeof(double));
System.Console.Readline();
}
}
}
语句
1.块
ints1,s2;
s1=0;
s2=0;
for(inti=0;i<100;i++)
{
if(i%2==0)
s1+=i;
else
s2+=i;
}
2.声明语句
intnum1,num2;
stringstr="Hello";
3.表达式语句
int[]num=newint[10];
inti=0;
i++;
4.选择语句
ifnum1,num2,max;
num1=3;
num2=4;
if(num1>num2)
max=num1;
else
max=num2;
5.迭代语句
也叫循环语句,重复执行嵌入语句,有whiledoforforeach语句
ints=0
for(inti=0;i<100;i++)
{
s+=i;
}
6.跳转语句
用于传递程序控制,有break,continue,goto,throw,return语句
intnum=5
switch(num)
{
case1:
System.Console.WriteLine("优");
case2:
System.Console.WriteLine("良");
case3:
System.Console.WriteLine("中");
break;
}
7.Try-catch语句
8.用于捕捉在块的执行期间发生的异常,并且,Try-catch语句用于指定一个终止代码块,不管异常是否出现,它总被执行
bytec=255;
try
{
b++;
}
catch(Exceptione)
{
Console.WriteLine(e.Message);
}
8.check和uncheck语句
用于控制整形算数运算和转换的溢出检查
9.lock语句
用于获取给定对象的互斥锁,执行语句,然后释放该锁
classAccount
{
decimalb;
publicvoidWithdraw(decimala)
{
lock(this)
{
if(a>b)
{
thrownewException("Insufficientfunds");
}
b-=a;
}
}
}
1.Using语句
用于获取一个资源,执行一个语句,然后处理该资源
staticvoidMain()
{
using(TextWritert=File.CreateText("test.txt"))
{
t.WriteLine("Writeone");
t.WriteLine("Writetwo");
t.WriteLine("Writethree");
}
}
块和作用域
选择和循环语句
C#中的循环语句包括,whiledo-whileforforeach
1.If语句(主要用于求布尔值)
staticvoidMain(string[]args)
{
if(args.Length==0)
Console.WriteLine("Noargs");
else
Console.WriteLine("Args");
}
例:
创建一个控制台的应用程序,使用if语句求3个数的最大数,在控制台项目Program.cs文件的main函数输入
staticvoidMain(string[]args)
{
inta,b,c,max;
if(a>b)
{
if(a>c)
max=a;
else
max=c;
}
else
{
if(b>c)
max=b;
else
max=c;
}
Console.WriteLine(Max);
System.Console.ReadLine();
}
usingSystem;
usingSystem.Collections.Generic;
usingSystem.Linq;
usingSystem.Text;
namespace_1._1
{
classProgram
{
staticvoidMain(string[]args)
{
inta,b,c,max;
a=7;b=6;c=13;
if(a>b)
{
if(a>c)
max=a;
else
max=c;
}
else
{
if(b>c)
max=b;
else
max=c;
}
Console.WriteLine(max);
System.Console.ReadLine();
}
}
}
Switch语句
例:
创建一个控制台应用程序,演示switch语句的使用方法
usingSystem;
usingSystem.Collections.Generic;
usingSystem.Linq;
usingSystem.Text;
namespace_1._1
{
classProgram
{
staticvoidMain(string[]args)
{
intcj;
cj=98;
switch(cj/10)
{
case9:
Console.WriteLine("优?
");
break;
case8:
Console.WriteLine("良?
");
break;
case7:
Console.WriteLine("中D");
break;
case6:
Console.WriteLine("及°格?
");
break;
default:
Console.WriteLine("不?
及°格?
");
break;
}
System.Console.WriteLine();
}
}
}