06-Tong Quan Ve Ngon Ngu C

1TRNG I HC BCH KHOA H NIVIN CNG NGH THNG TIN V TRUYN THNG

TIN HC I CNGBi 6. Tng quan v ngn ng C

Ni dung

6.1. Lch s pht trin

6.2. Cc phn t c bn ca ngn ng C

6.3. Cu trc c bn ca chng trnh C

6.4. Bin dch chng trnh C

6.5. Trnh bin dch Turbo C++

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6.1. Lch s pht trin





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6.1. Lch s pht trin

Ra i ti phng th nghim BELL ca tp on AT&T (Hoa K)

Do Brian W. Kernighan v Dennis M. Ritchie pht trin vo u 1970, hon thnh 1972

C da trn nn cc ngn ng BCPL (Basic Combined Programming Language) v ngn ng B.

Tn l ngn ng C nh l s tip ni ngn ng B.

26.1. Lch s pht trin

c im ca ngn ng lp trnh C

Ngn ng lp trnh h thng

Tnh kh chuyn, linh hot cao

C th mnh trong x l d liu s, vn bn,c s d liu

C thng c s dng vit ccchng trnh h thng

H iu hnh Unix c 90% m C, 10% hpng

Cc trnh iu khin thit b (device driver)

X l nh 55 6

6.1. Lch s pht trin

1978: C c gii thiu trong phin bn u ca cun sch "The C programming language"

Sau , C c b sung thm nhng tnh nngv kh nng mi ng thi tn ti nhiu phin bn nhng khng tng thch nhau.

Nm 1989, Vin tiu chun quc gia ca Hoa K (American National Standards Institute - ANSI) cng b phin bn chun ha ca ngn ng C: ANSI C hay C chun hay C89

6.1. Lch s pht trin

Cc phin bn ngn ng C

ANSI C: C chun (1989)

Cc phin bn khc thng b sung thmth vin ca ANSI C

Hin nay cng c nhiu phin bn ca ngn ngC khc nhau, gn lin vi mt b chng trnhdch c th ca ngn ng C

Turbo C++ v Borland C++ ca Borland Inc.

MSC v VC ca Microsoft Corp.

GCC ca GNU project

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6.1. Lch s pht trin





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3V d

#include

#include

void main(){

printf(Hello World\n);

getch();

}

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6.2.1. Tp k t

Tp k t l tp cc phn t c bn to nn chng trnh

T hp cc k t t

Lin kt cc t theo c php cu lnh

T chc cc cu lnh chng trnh

V d:

include, void, main

printf(), getch();

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6.2.1. Tp k t

Tp k t trong C

26 ch ci hoa:A B C ... X Y Z

26 ch ci thng:a b c x y z.

10 ch s: 0 1 2 3 4 5 6 7 8 9.

Cc k hiu ton hc:+ - * / = < >

Cc du ngn cch: . ; , : space tab

Cc du ngoc:( ) [ ] { }

Cc k hiu c bit:_ ? $ & # ^ \ ! ~ .v.v.

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6.2.2. T kha

T kha (keyword)

C sn trong mi ngn ng lp trnh

Dnh ring cho cc mc ch xc nh

t tn cho kiu d liu: char, int, float, double

M t cc lnh, cc cu trc lp trnh: if, else, switch, case, while, do

Ch :

Tt c t kha trong C u vit bng ch ci thng

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46.2.2. T kha

T kha hay dng trong Turbo C

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6.2.3. nh danh

nh danh (Identifier hoc cn gi l Tn) l mt dy cc k t dng gi tn cc i tng trong chng trnh.

Cc i tng trong chng trnh Bin

Hng s

Hm

Kiu d liu (s lm quen cc mc sau)

nh danh c th c t bi Ngn ng lp trnh cc t kha

Ngi lp trnh14

6.2.3. nh danh

Quy tc t tn nh danh trong C

Cc k t c s dng: ch ci, ch s v du gch di _ (underscore)

Bt u ca nh danh phi l ch ci hoc du gch di _, khng c bt u nh danh bng ch s.

nh danh do ngi lp trnh t khng c trng vi cc t kha ca C

Ch : C l ngn ng c phn bit ch hoa v ch thng

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6.2.3. nh danh

V d

nh danh hp l:

i, x, y, a, b, _function, _MY_CONSTANT, PI, gia_tri_1

nh danh khng hp l

1_a, 3d, 55x (bt u bng ch s)

so luong, ti le (c du cch - k t khng hp l)

int, char (trng vi t kha ca ngn ng C)

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56.2.3. nh danh

Mt s quy c (code convention) Nn s dng du gch di hoc vit hoa phn

tch cc nh danh gm nhiu t

nh danh nn c tnh gi nh

Quy c thng c s dng:

Hng s dng ch ci hoa

Cc bin, hm, cu trc dng ch ci thng

V d

nh danh Loi i tng

HANG_SO_1, CONSTANT_2 Hng s

a, b, i, j, count Bin

nhap_du_lieu, tim_kiem, xu_li Hm

sinh_vien, mat_hang Cu trc17

Sohoanhao

SOHOANHAO

so_hoan_hao

SoHoanHao

SoHoAnhAo

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6.2.4. Cc kiu d liu

nh ngha:

Kiu d liu cho bit cch lu tr d liu trong b nh, di gi tr v cc php ton c th thc hin trn d liu.

V d:

Kiu d liu int (s nguyn) trong C

Mt d liu thuc kiu d liu int

L mt s nguyn c du

2 byte

Nhn gi tr t t - 32,768 (- 215) n 32,767 (215 - 1)

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6.2.4. Cc kiu d liu

V d (tip) Mt s php ton c nh ngha trn kiu d liu

int ca C

Tn php ton K hiu

o du -

Cng +

Tr -

Nhn *

Chia ly phn nguyn /

Chia ly phn d %

So snh >, =,

6V d

#include

#include

#define PI 3.14

void main(){

float r, s;

printf(Nhap ban kinh hinh tron:);

scanf(%f,&r);

s = PI * r * r;

printf(Dien tich hinh tron %f\n,s);

getch();

} 21

6.2.5. Hng s

nh ngha:

hng (constant) l i lng c gi tr khng i trong chng trnh.

Biu din hng s nguyn: trong C, mt hng s nguyn c th biu din di 3 dng

Dng thp phn

Dng thp lc phn

Dng bt phn

Gi tr thp phn Gi tr thp lc phn Gi tr bt phn

2007 0x7D7 03727

396 0x18C 061422

6.2.5. Hng s

Biu din hng s thc: trong C, mt hng s thc c th biu din di 2 dng

Dng s thc du phy tnh

Dng s thc du phy ng

V d

S thc du phy tnh S thc du phy ng

3.14159 31.4159 E-1

123.456 12.3456 E+1 hoc 1.23456 E+2

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6.2.5. Hng s

Biu din hng k t: trong C, mt hng k t c th biu din theo hai cch

Bng k hiu ca k t t gia hai du nhy n

Bng s th t ca k t trong bng m ASCII (s nguyn -> tun th quy tc biu din hng s nguyn)

V d

K t cn biu din Cch 1 Cch 2

Ch ci A A 65, 0x41, 0101

Du nhy n \ 39, 0x27, 047

K t tab \t 0, 0x09, 011

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76.2.5. Hng s

Biu din hng xu k t:

Hng xu k t c biu din bi dy cc kt thnh phn c trong xu v c ttrong cp du nhy kp.

V d:

ngon ngu lap trinh C

Tin hoc dai cuong

Dai hoc Bach Khoa Ha Noi

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V d

#include

#include

void main(){

float a, b, x;

printf(Nhap he so a=);scanf(%f,&a);

printf(Nhap he so b khac 0, b=);scanf(%f,&b);

x = -b/a;

printf(Nghiem cua phuong trinh %f,x);

getch();

} 26

6.2.6. Bin

nh ngha:

Bin (variable) l i lng m gi tr c th thay i trong chng trnh.

Ch :

Hng s v bin c s dng lu tr d liu trong chng trnh

Hng s v bin phi thuc mt kiu d liu no

Hng s v bin u phi t tn theo quy tc

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6.2.7. Hm

M t:

Hm (function) l mt chng trnh con c chc nng nhn d liu u vo (cc tham s u vo), thc hin mt chc nng no v a ra cc kt qu.

Hm ngha K hiu ton hc V d

Pow(x,y) X m y Xy Pow(2,3)=8

Sin(x) Sin ca x Sinx Sin(0)=0

Cos(x) Cos ca x Cosx Cos(0)=1

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86.2.8. Biu thc

nh ngha:

Biu thc l s ghp ni cc ton t (operator) v cc ton hng (operand) theo mt quy tc xc nh.

Cc ton hng c th l bin, hng

Cc ton t rt a dng: cng, tr, nhn, chia..

V d: biu thc tnh th tch hnh ch nht

chieu_dai * chieu_rong * chieu_cao

- chieu_dai, chieu_rong, chieu_cao l cc hng hoc bin s ng vai tr ton hng

- Php * ng vai tr ton t29

6.2.9. Cu lnh

Cu lnh (statement) din t mt hoc mtnhm cc thao tc trong gii thut.

Chng trnh c to thnh t dy cccu lnh.

Cui mi cu lnh bt buc c du chmphy ; nh du kt thc cu lnh

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6.2.9. Cu lnh

Phn nhm: Nhm cc cu lnh n: nhng cu lnh

khng cha cu lnh khc. V d: php gn,php cng, php tr

Nhm cc cu lnh phc: nhng cu lnhcha cu lnh khc.

V d: lnh khi t trong cp ngoc nhn { }

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6.2.10. Ch thch

Ch thch (comment):

Li m t, gii thch vn tt cho mt cu lnh,mt on chng trnh hoc c chng trnh

Gip vic c v hiu chng trnh d dnghn

Ch thch khng phi l cu lnh -> khng nhhng ti chng trnh

Cch vit ch thch: trong C c hai cch

Ch thch mt dng: s dng //

Ch thch nhiu dng: s dng /* v */

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9Ni dung

6.1. Lch s pht trin





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V d

#include //Khai bao tep tieu devoid main(){// Khai bao cac bienint a, b; //int : kieu so nguyeint tong, hieu, tich;

// Nhap vao tu ban phim 2 so nguyen

printf(\nNhap vao so nguyen thu nhat: ); //In ra man hinh

scanf(%d,&a); //Doc tu phim gia tri cua a

printf(\n Nhap vao so nguyen thu hai: );

scanf(%d,&b);34

V d

// Tinh tong, hieu, tich cua 2 so do

tong = a+b; hieu = a b;tich = a*b;

// Hien thi cac gia tri ra man hinh

printf(\n Tong cua 2 so vua nhap la %d, tong);

printf(\n Hieu cua 2 so vua nhap la %d, hieu);

printf(\n Tich cua 2 so vua nhap la %d, tich);

// Doi nguoi dung an phim bat ki

getch();

}35

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Gm 6 phn c th t nh sau:

Phn1: Khai bo tp tiu : #include

Phn 2: nh ngha kiu d liu mi: typedef ...

Phn 3: Khai bo cc hm nguyn mu

Phn 4: Khai bo cc bin ton cc

Phn 5: Hm main()

Phn 6: Ni dung cc hm khai bo


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Phn 1: Khai bo tp tiu :

Thng bo cho chng trnh dch bit l chng trnh c s dng nhng th vin no.

VD: #include

#include


Th vin Chc nng

stdio.h Cc hm vo/ra c bn

conio.h Cc hm giao tip ngi dng s dng MS-DOS API

math.h Cc hm ton hc c bn

ctype.h Cc hm x l k t

string.h Cc hm x l xu

stdlib.h Cc hm tin ch

time.h Cc hm iu khin thi gian 38

Phn 2: nh ngha cc kiu d liu mi

nh ngha cc kiu d liu mi (nu cn) dng cho c chng trnh.

Phn 3: Khai bo cc hm nguyn mu: Gip cho chng trnh dch bit c nhng

thng tin c bn ca cc hm s dng trong chng trnh.

Phn 4: Khai bo cc bin ton cc V d:

int a, b;

int tong, hieu, tich;


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Phn 5: Hm main( )

Khi thc hin, chng trnh s bt u bng vic thc hin cc lnh trong hm main( ).

Trong hm main( ) c th c lnh gi ti cc hm khc.

Phn 6: Ni dung ca cc hm khai bo

Ci t (vit m) cho cc hm khai bo nguyn mu phn 3.

6.3. Cu trc c bn ca chng trnh C Vit mt chng trnh p

Ch thch m t hm/chng trnh:

Chc nng

u vo

u ra

nh du bn quyn

Ch thch cc bin quan trng

Ch thch cc bc x l d liu theo thut ton

Li dng cho cc lnh lng nhau

nh danh i tng r rng

Module ha chng trnh

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6.1. Lch s pht trin





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Preprocessor Loi b cc ch thch Dch cc ch th tin x l bt u l #

C Compiler Bin dch m ngun thnh m assembly.

Assembler To ra m object.

Trn UNIX file .o Trn MS-DOS file.OBJ

Link Editor Nu tp ngun tham chiu n cc hm

th vin/hm c nh ngha th Link editor kt hp cc hm ny vi hm main() to ra tp c th thc thi c

Trong MS-DOS l file .exe


Ni dung

6.1. Lch s pht trin





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6.5.1. Gii thiu

Trnh bin dch (compiler): dch m ngun (source code) thnh file thc thi

Cc trnh bin dch C ph bin

Turbo C++ ca hng Borland

MSC ca Microsoft

GCC ca GNU

Dev C++ ca Bloodshed Software

Turbo C++ c nhiu phin bn

Phin bn la chn: Turbo C++ 3.0

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6.5.2. Ci t v s dng Turbo C++ 3.0

Ci t

B1: Chun b b ci ca Turbo C++ 3.0 (~4 MB) Copy b ci ny vo my ca bn, gi s vo th mc C:\TC_Setup.

B2: n th mc cha b ci Turbo C++ 3.0 (nh gi s trn l C:\TC_Setup) v kch hot file INSTALL.EXE chy chng trnh ci t. Chng trnh ci t s yu cu bn ch ra a trn cha b ci Turbo C++ 3.0

Enter the SOURCE drive to use:

Hy nhp vo tn a, chng hn C (ta b ci Turbo C++ 3.0 th mc C:\TC_Setup).

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B3: Chng trnh yu cu bn nhp vo ng dn ti th mc cha cc file ca Turbo C++ 3.0

Enter the SOURCE Path:

Thng thng chng trnh s t tm cho bn, v bn ch cn n Enter chuyn sang bc tip theo.

B4: Xc nh th mc ci t. Th mc ny s cha cc file ca Turbo C++ 3.0 bn s dng sau ny.

Directories [C:\TC]

Option[IDE CMD LIB CLASS BGI HELP EXMPL]

http://sites.google.com/site/buitrongtung

HD.zip

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Start Installation Th mc ci t mc nh s l \TC nm trn th mc

gc ca a cha b ci. Nu bn mun thay i th mc ci t th hy dng cc phm v di chuyn hp sng n phn Directories, g Enter v nhp vo ng dn mi, sau n phm Esc tr v.

Dng cc phm v di chuyn hp sng n phn Start Installation v n Enter. Chng trnh s t ng thc hin v hon tt qu trnh ci t cho bn.

Lu : Bn c th copy ton b th mc ci t ca Turbo C++ 3.0 v my v s dng, nhng bn phi ch cho Turbo C++ bit ng dn ti cc tp tiu v cc tp th vin bng cch vo menu Option, chn Directories.

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Giao din s dng ca chng trnh

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Video: Setup TurboC


Khi ng chng trnh: tm n th mc BIN trong th mc ci t v chy file TC.EXE

To ca s son tho mi: chn menu File (hoc n Alt-F), sau chn mc New m ca s son tho mi.

G chng trnh ngun vo ca s son tho

Lu chng trnh vi tn file,v d: HelloWorld.cpp

Bin dch chng trnh: bm F9

Chy chng trnh: Ctrl + F9 50


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Video: S dng TurboC

Tho lun

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06-Tong Quan Ve Ngon Ngu C