QUY TẮC LẬP TRÌNH

8/4/2019 QUY TC LP TRNH

1/22

QUY TC LP TRNH

Console Application


2/22

QUY TC LP TRNH

Khi to mt chng trnh trong C# chng tann thc hin theo nhng bc nh sau: Bc1: Xc nh mc tiu ca chng trnh

Bc 2: Xc nh nhng phng php gii quytvn

Bc 3: To mt chng trnh gii quyt vn

Bc 4: Thc thi chng trnh xem kt qu


3/22

NG DNG Console Application

L ng dng vi ngi dng thng qua bnphm khng c giao din ngi dng (UI)


4/22

PHN B SUNG

1. Namespace

2. T kho using3. T kho static4. T kho this5. Ch thch (Commnet)

6. Phn bit ch thng v ch hoa7. Ton t .8. Kiu chui k t


5/22

Namespace

.Net cung cp mt th vin cc class rt s.Trong Console l mt class nh trong thvin class ny.

Mi class c mt tn ring, v vy ngi lptrnh khng th no nh ht tn cc classtrong .Net. gii quyt vic ny l vic to ramt namespace. Namespace s hn ch phmvi ca mt tn, lm cho tn ny ch c nghatrong vng nh ngha.


6/22

T kho using

khng phi vit namespace cho tng itng ta dng t kho using.

Ta c th dng t kho sau u chngtrnh : using System;

Khi thay v vit y : System.Console. tach cn vit Console.


7/22

T kho static

T kho static ch ra rng hm Main c thc gi m khng cn phi thc hin to itng lp m n ng trong .


8/22

T kho this

T kho this dng tham chiu n th hinhin hnh ca i tng.


9/22

Ch thch (comment)

Mt chng trnh c vit tt th phi cch thch cc on m lnh c vit.

Mc ch l lm cho on m lnh ngun rrng v d hiu.

C hai loi ch thch: Ch thch mt dng: //

Ch thch nhiu dng: /.../


10/22

Phn bit ch thng ch hoa

C# l ngn ng phn bit ch thng ch hoa


11/22

Ton t .

Ton t . c dng truy cp n mtphong thc hay d liu trong mt class vngn cch gia tn class v mt namespace.

V d:

System.Console.WriteLine();

namespace class

Phng

thc


12/22

Kiu chui k t

Khai bo chui hng:

string = ;

V d: string tentruong = Cao dang Tran HungDao" ;


13/22

Kiu chui k t

Khai bo bin kiu chui: string *= "Noi dung chuoi hang"+ ;

V d: string hoten = "Nguyen Van Teo" ;

Nhp chui:

= System.Console.ReadLine() ;

V d: hoten = System.Console.ReadLine() ;


14/22

Kiu chui k t

Xut chui

System.Console.WriteLine("Chuoi") ;

V d: System.Console.WriteLine("Do dai cua chuoi la:") ;


15/22

Mt s thao tc trn chui

Phngthc ngha

Length Chiudi ca chui

Substring() Lychui con

ToLower() Trv bn sao ca chui kiu ch thngToUpper() Trli bn sao ca chui kiu ch in hoa


16/22


using System;

class Hoten

{

static void Main()

{ //Khai bo binstring Hoten;

//Nhpgi tr cho bin chui

Console.Write(Nhapho va ten);

Hoten = Console.ReadLine();//Thao tc trn chui

string HT = Hoten.ToUpper();

string ht = Hoten.ToLower();

int dodai = Hoten.Length;


17/22


//Xut ra mn hnh

Console.WriteLine("Ho va Ten (chu IN HOA): {0}", HT) ;

Console.WriteLine("Ho va Ten (chu thuong): {0}", ht) ;

Console.WriteLine("Do dai Ho va Ten la: {0}",dodai) ;

}

}


18/22

Kiu d liu

C# chia kiu d liu thnh hai tp hp kiu dliu chnh:

Kiu xy dng sn (buil-in): do ngn ng cungcp cho ngi lp trnh.

Kiu do ngi dng nh ngha (user defined):do ngi lp trnh to ra.


19/22

Kiu d liu dng sn

Kiu C# Sbyte Kiu .Net M t

byte 1 Byte Snguyn dng khng du t 0 n 255

char 2 Char K t Unicode

bool 1 Boolean Gi tr logic True/False

sbyte 1 Sbyte Snguyn c du t -128 n 127short 2 Int16 Snguyn c du t -32768 n 32767

ushort 2 Uint16 Snguyn dng khng du t 0 n 65535

int 4 Int32 S nguyn c du t -2.147.483.647 dn2.147.483.647

uint 4 Uint32 S nguyn khng du t 0 dn 4.294.967.295

float 4 Single Kiu du chm dng, gi tr xp x t-3.4E-38 dn 3.4E38, vi 7 ch s c nghia

double 8 Double Kiu du chm dng c d chnh xc gpdi, gi tr xp x t -1.7E-308 dn 1.7E308,vi 15, 16 ch s c nghia


20/22

Kiu d liu dng sn

Kiu C# Sbyte Kiu .Net M t

decimal 8 Decimal C d chnh xc dn 28 con s v gi tr thpphn, duc dng trong tnh ton ti chnh, kiuny di hi phi c hu t m hay M

long 8 Int64 Kiu s nguyn c du c gi tr trong khong -9.223.370.036.854.775.808 dn9.223.372.036.854.775.807

ulong 8 Uint64 S nguyn khng du t 0 dn 0xfffffffffffffff


21/22

Bng trnh by cc k t c bit

K t ngha

\ Dunhy n

\ Du nhy kp

\\ Du cho

\0 K t rng (null)\a Alert

\b Backspace

\f Sang trang form feed

\n Dng mi\r u dng

\t Tab ngang

\v Tab dc


22/22

Chuyn i kiu d liu

V d a:

short x = 10 ; int y = x ; // chuyn di ngm dnh

V d b:

short x ; int y = 100 ; x = (short) y ; // p kiutung minh, trnh bin dch khng bo li

V d c:

short x ; int y = 100 ; x = y ; // khng bin dch,gy ra li

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