1) value transfer call and Reference call
Copy codeThe Code is as follows: using System;
Class MethodCall
{
Public static void Main ()
{
/*
* The parameter types include in, ref, and out. The default value is in.
* After the in type is modified in the sub-method, the value in the main method does not change.
* If the ref type is modified in the submethod, the value in the primary method also changes.
* The variables in the out main method do not need to be initialized.
*
*/
Int a = 1, B = 2, c;
Console. WriteLine ("Before Method Call: a = {0}, B = {1}, c is not assigned a value", a, B );
AMethod (a, ref B, out c );
Console. WriteLine ("After Method Call: a = {0}, B = {1}, c = {2}", a, B, c );
Console. Read ();
}
Public static void AMethod (int x, ref int y, out int z)
{
X = 110;
Y = 120;
Z = 119;
}
}
:
2) print triangle
Copy codeThe Code is as follows: using System;
Public class Hello
{
Public static void Main ()
{
Console. Write ("Enter the number of rows :");
Int lines = int. Parse (Console. ReadLine ());
Console. WriteLine ("");
For (int I = 1; I <= lines; I ++)
{
For (int k = 1; k <= lines-I; k ++)
Console. Write ("");
For (int j = 1; j <= I * 2 + 1; j ++)
Console. Write ("*");
Console. WriteLine ("");
}
Console. ReadLine ();
}
}
:
3) recursive factorial
Copy codeThe Code is as follows: using System;
Class Factor
{
Public static void Main ()
{
For (int I = 1; I <= 10; I ++)
Console. WriteLine ("the Factorial of {0} is {1}", I, Factorial (I ));
Console. Read ();
}
Public static long Factorial (long n)
{
If (n = 1)
Return 1;
Else
Return n * Factorial (n-1 );
}
}
:
4) polymorphism
Copy codeThe Code is as follows: using System;
Class Car
{
Public virtual void Drive ()
{Console. WriteLine ("Drive Car ");}
}
Class Truck: Car
{
Public override void Drive ()
{Console. WriteLine ("Drive Truck ");}
}
Class Client
{
Public static void Main ()
{
Car c = new Truck ();
C. Drive (); // polymorphism determines that the Drive method of Truck will be called.
Console. Read ();
}
}
:
5) method Overloading
Copy codeThe Code is as follows: using System;
Class Client
{
Public static void Main ()
{
// Reload indicates that the method name is the same and the method signature is different.
Console. WriteLine (Add (100,50 ));
Console. WriteLine (Add ("100", "50 "));
Console. Read ();
}
Public static string Add (string a, string B)
{
Return a + "add" + B;
}
Public static int Add (int a, int B)
{
Return a + B;
}
}
:
6) constructor
Copy codeThe Code is as follows: using System;
Public class Person
{
Public string name = "";
Public int age = 0;
// Default constructor
Public Person ()
{
}
// Overload the constructor (1)
Public Person (int Age)
{
This. age = Age;
}
// Overload the constructor (2)
Public Person (int Age, string Name)
{
This. age = Age;
This. name = Name;
}
Public void ShowInfo ()
{
Console. WriteLine ("name:" + name );
Console. WriteLine ("age:" + age );
}
}
Class Client
{
Public static void Main ()
{
Person p1 = new Person ();
P1.ShowInfo ();
Console. WriteLine ("*************************");
Person p2 = new Person (25 );
P2.ShowInfo ();
Console. WriteLine ("*************************");
Person p3 = new Person (25, "");
P3.ShowInfo ();
Console. Read ();
}
}
:
7) static and non-static
Copy codeThe Code is as follows: using System;
Class StaticHello
{
Public static void SayHello ()
{Console. WriteLine ("Static Hello ");}
}
Class NonStaticHello
{
Public void SayHello ()
{Console. WriteLine ("Non Static Hello ");}
}
Class Client
{
Public static void Main ()
{
// The "class name. Method" should be used for static method calls"
StaticHello. SayHello ();
// Use "Instance name. Method" for non-static method calls"
NonStaticHello h = new NonStaticHello ();
H. SayHello ();
Console. Read ();
}
}
:
8) Table 9
Copy codeThe Code is as follows: using System;
Public class JiuJiuBiao
{
Public static void Main (string [] args)
{
Int I, j;
For (I = 1; I <10; I ++)
{
For (j = 1; j <10; j ++)
{
Console. Write ("{0: D1} * {1: D1} = {2, 2}", I, j, I * j );
}
Console. WriteLine ("");
}
Console. ReadLine ();
}
}
:
9) bubble sort
Copy codeThe Code is as follows: using System;
Class ArraySort
{
Public static void Main ()
{
Int [] d = };
Int temp;
// Sort by bubble
For (int I = 0; I <d. Length; I ++)
For (int j = I + 1; j <d. Length; j ++)
If (d [I] <d [j])
{
Temp = d [I];
D [I] = d [j];
D [j] = temp;
}
// Output the sorting result
Foreach (int I in d)
Console. Write ("{0},", I );
Console. Read ();
}
}
:
10) Quantity of Quality
Copy codeThe Code is as follows: using System;
Class Factor
{
Public static void Main ()
{
For (int I = 1; I <= 100; I ++)
If (IsPrime (I ))
Console. WriteLine (I );
Console. Read ();
}
Public static bool IsPrime (int n)
{
For (int I = 2; I <= Math. Sqrt (n); I ++)
If (n % I = 0)
Return false;
Return true;
}
}
:
11) sort by API (1)
Copy codeThe Code is as follows: using System;
Using System. Collections;
Public class Person: IComparable
{
Public int ID;
Public string Rank;
Public Person (int id, string rank)
{This. ID = id; this. Rank = rank ;}
# Region IComparable Members
/*
* The IComparable interface has only one method: CompareTo. CompareTo Method
* Only one object type parameter is received, which means that it can receive any class
* Type data (the object is the parent class of all classes). This method returns
* Integer value, meaning:
*
* 1) the value is smaller than zero and the current instance (this) is smaller than the obj object.
* 2) equal to zero, the current instance (this) is equal to the obj object
* 3) the value is greater than zero. The current instance (this) is greater than the obj object.
*
* The IComparable interface has been implemented for Int32, int16..., String, Decimal, and other data types.
*/
Public int CompareTo (object obj)
{
Person p = (Person) obj;
Return this. ID. CompareTo (p. ID );
}
# Endregion
}
Class SortArrayList
{
Static void Main (string [] args)
{
ArrayList list = new ArrayList ();
List. Add (new Person (6, "Long queue "));
List. Add (new Person (3, "head "));
List. Add (new Person (4, ""));
List. Add (new Person (5, "brigade chief "));
List. Add (new Person (7, "persistent connections "));
List. Add (new Person (1, "military chief "));
List. Add (new Person (2, "battalion commander "));
List. Add (new Person (8, "teacher "));
List. Sort ();
Console. WriteLine ("After Sorting ");
Foreach (Person person in list)
{
Console. WriteLine ("ID:" + person. ID. ToString () + ", Rank:" + person. Rank );
}
}
}
:
12) sort by API (2)
Copy codeThe Code is as follows: using System;
Using System. Collections;
Public enum enuSortOrder
{IDAsc, IDDesc, RankAsc, RankDesc}
Public class Person: IComparable
{
Public static enuSortOrder intSortOrder = enuSortOrder. IDAsc;
Public int ID;
Public string Rank;
Public Person (int id, string rank)
{This. ID = id; this. Rank = rank ;}
# Region IComparable Members
/*
* The IComparable interface has only one method: CompareTo. CompareTo Method
* Only one object type parameter is received, which means that it can receive any class
* Type data (the object is the parent class of all classes). This method returns
* Integer value, meaning:
*
* 1) the value is smaller than zero and the current instance (this) is smaller than the obj object.
* 2) equal to zero, the current instance (this) is equal to the obj object
* 3) the value is greater than zero. The current instance (this) is greater than the obj object.
*
* The IComparable interface has been implemented for Int32, int16..., String, Decimal, and other data types.
*/
Public int CompareTo (object obj)
{
Person p = (Person) obj;
Switch (int) intSortOrder)
{
Case (int) enuSortOrder. IDAsc:
Return this. ID. CompareTo (p. ID );
Case (int) enuSortOrder. IDDesc:
Return p. ID. CompareTo (this. ID );
Case (int) enuSortOrder. RankAsc:
Return RankCompare (this. Rank, p. Rank );
Case (int) enuSortOrder. RankDesc:
Return RankCompare (p. Rank, this. Rank );
Default:
Return this. ID. CompareTo (p. ID );
}
}
Private int RankCompare (string rank1, string rank2)
{
Int intRank1 = ConvertRankToInt (rank1 );
Int intRank2 = ConvertRankToInt (rank2 );
If (intRank1 <intRank2)
Return-1;
Else if (intRank1 = intRank2)
Return 0;
Else
Return 1;
}
Private int ConvertRankToInt (string rank)
{
If (rank = "")
Return 8;
Else if (rank = "military chief ")
Return 7;
Else if (rank = "")
Return 6;
Else if (rank = "brigade chief ")
Return 5;
Else if (rank = "")
Return 4;
Else if (rank = "battalion commander ")
Return 3;
Else if (rank = "connection length ")
Return 2;
Else
Return 1;
}
# Endregion
}
Class SortArrayList
{
Static void Main (string [] args)
{
ArrayList list = new ArrayList ();
List. Add (new Person (6, "Long queue "));
List. Add (new Person (3, "head "));
List. Add (new Person (4, ""));
List. Add (new Person (5, "brigade chief "));
List. Add (new Person (7, "persistent connections "));
List. Add (new Person (1, "military chief "));
List. Add (new Person (2, "battalion commander "));
List. Add (new Person (8, "teacher "));
List. Sort ();
Console. WriteLine ("Sort By ID Asc :");
Foreach (Person person in list)
{
Console. WriteLine ("ID:" + person. ID. ToString () + ", Rank:" + person. Rank );
}
Console. WriteLine ("----------------------------");
Console. WriteLine ("Sort By ID Desc :");
Person. intSortOrder = enuSortOrder. IDDesc;
List. Sort ();
Foreach (Person person in list)
{
Console. WriteLine ("ID:" + person. ID. ToString () + ", Rank:" + person. Rank );
}
Console. WriteLine ("----------------------------");
Console. WriteLine ("Sort By Rank Asc :");
Person. intSortOrder = enuSortOrder. RankAsc;
List. Sort ();
Foreach (Person person in list)
{
Console. WriteLine ("ID:" + person. ID. ToString () + ", Rank:" + person. Rank );
}
Console. WriteLine ("----------------------------");
Console. WriteLine ("Sort By Rank Desc :");
Person. intSortOrder = enuSortOrder. RankDesc;
List. Sort ();
Foreach (Person person in list)
{
Console. WriteLine ("ID:" + person. ID. ToString () + ", Rank:" + person. Rank );
}
}
}
:
13) Attribute and method Scope
Copy codeThe Code is as follows: using System;
Class Base
{
/*
* Public is accessible to all classes.
* The private accessible range is the current class.
* The accessible scope of protected is the current class and its subclass.
*/
Public string name = "Tom ";
Private double salesary = 1500;
Protected int age = 20;
Public virtual void ShowInfo ()
{
Console. WriteLine (this. name); // yes, because name is public
Console. WriteLine (this. salary); // yes. salary is private and can be accessed in the Base class.
Console. WriteLine (this. age); // yes, because age is of the protected type, which can be accessed in the subclass.
}
}
Class Derived: Base
{
Public override void ShowInfo ()
{
Console. WriteLine (this. name); // yes, because name is public
// Console. WriteLine (this. salary); // No. salary is private and cannot be accessed when the Base is exceeded.
Console. WriteLine (this. age); // yes, because age is of the protected type, which can be accessed in the subclass.
}
}
Class Client
{
Public static void Main ()
{
Base B = new Base ();
Console. WriteLine (B. name); // yes, because name is public
// Console. WriteLine (this. salary); // No. salary is private and cannot be accessed when the Base is exceeded.
// Console. WriteLine (this. age); // No, because age is protected and Client is not a subclass of Base
Console. WriteLine ("========================= ");
B. ShowInfo ();
Console. WriteLine ("========================= ");
Derived d = new Derived ();
D. ShowInfo ();
}
}
:
15) fields and attributes
Copy codeThe Code is as follows: using System;
Class SumToHundred
{
Public static void Main ()
{
Int sum = 0;
For (int I = 1; I <= 100; I ++)
Sum + = I;
Console. WriteLine (sum );
}
}
PicCopy codeThe Code is as follows: using System;
Class Account
{
Private double balance = 0; // Field
Public double Balance // attribute
{
Get {return balance ;}
Set {balance = value ;}
}
/* ===================================================== ======================================
* The get and set methods can be modified to control access.
* Example:
*
* 1) read-only attributes
* Public double Balance // attribute
*{
* Get {return balance ;}
* Set {}
*}
*
* 2) read/write control
* Public double Balance
*{
* Get
*{
* If (Console. ReadLine () = "1234 ")
* Return balance;
* Else
* Returned-9999999;
*}
* Set {}
*}
* ===================================================== ======================================
*/
Public void Deposit (double n)
{This. balance + = n ;}
Public void WithDraw (double n)
{This. balance-= n ;}
}
Class Client
{
Public static void Main ()
{
Account a = new Account ();
A. Balance = 1000; // read/write attributes, because the property Balance is public
// A. balance = 1000; // fields cannot be read or written, because the field balance is private
A. WithDraw (500 );
A. Deposit (2000 );
Console. WriteLine (a. Balance );
}
}
