Transcript Computer Fundamentals - Primeasia University

CSC 202
Computer Programming
Alphabets of C
Recall the alphabets of English language
 A to Z of English alphabet
 a to z
 0 to 9

+ - * / = % & #
! ? ^ “ ‘ ~ \ |
< > { } ( ) [ ]
: ; . ,
(blank space)
CSC 202
Computer Programming
Escape sequence: Special characters
Character
New line (example: typing)
Horizontal tab (example: typing)
Vertical tab
Backslash
Apostrophe
Quotation mark
Form feed
printf(“Hello \n world”);
printf(“hello \t world”);
Escape Sequence
\n
\t
\v
\\
\’
\”
\f
CSC 202
Identifier
Computer Programming
name of
Variable
name of
Function
Rules in naming an Identifier:
• First character of an Identifier must be a letter.
“, ‘
• Some characters cant be used. These are
-,
Examples of some valid identifiers:
Examples of some Invalid identifier ,
x, x12, sum, sum_add,
temperature, AREA , tax_rate,
5sum, add”ition, Order-no, Order no
Sum, SUm, a, a1, b , B
,
etc.
CSC 202
Computer Programming
Keywords
~ are reserved and can’t be used as identifier.
C Keywords
auto
extern
for
struct
continue
do
void
sizeof
char
int
goto
union
double
break
switch
default
return
static
else
if
case
typedef
long unsigned
short
while
Data type
C supports several types of data
–
–
–
–
–
Integer (2,3,4); int
Long integer (50000); long
Floating point numbers (1.2, 5.6); float
Long float numbers (100000.56787); double
Character (a,b,c,d)
Variable is data container. So at the time of variable declaration, we have
to mention which type of data is going to contain.
(
#include<stdio.h>
#include<conio.h>
void main(){
int a, b, sum;
a=2;
b=3;
sum=a+b;
Variable declaration
Input
Process
printf(“Jogfol is %d \n”,sum);
getch();
}
Output
CSC 202
Computer Programming
Variable declaration
int a;
int b = 56;
float temperature;
int num = 32767;
float temperature=32.5;
long bigNum =40040;
double fraction = 12 e-3;
char ch;
char ch =‘A’;
CSC 202
Computer Programming
Data type
Data type
Description
int
Integer (positive & negative) 2 bytes
unsigned int
long int
Positive Integer
Long integer
2 bytes
4 bytes
float
Floating point number
4 bytes
double
Double precision floating
point number
Single character
8 bytes
char
Typical memory
requirements
1 bytes
#include<stdio.h>
#include<conio.h>
void main(){
int num1= -23,num2=32767;
unsigned int pos1 =23,pos2=65535;
float div=3.4;
double bigNum=1.2e23;
printf(“Integers :\t %d %d \n”,num1,num2);
printf(“Positive numbers:\n %u %u \n”,pos1,pos2);
printf(“Floating point number:\t %f \n”,div);
printf(“Very Big number %lf \n”,bigNum);
getch();
}
CSC 202
Computer Programming
Array
Suppose you need to store a record which has thousand of integers. Now will you declare
thousand variables????
Array is a solution to such situation. It is an identifier that refers to a collection of data items.
Data items must all be of same type.
Scores
55
99
77
89
110 27
68
int scores[8]= {55,99,77,89,110,27,68,69};
Or
int scores[8];
scores[0]=55;
scores[1]=99;
69
#include<stdio.h>
#include<conio.h>
void main(){
int scores[8]= {55,99,77,89,110,27,68,69};
int pitScore;
int bobScore,noBall;
printf(“Border-Loyd champ trophy\n”);
printf(“----------Score Card------------\n”);
printf(“Pit \t %d of %d\n”,scores[0],scores[1]);
bobScore= scores[2];
noBall=scores[3];
printf(“Bob \t %d of %d\n”,scores[2],scores[3]);
getch();
}
Library function
• Carries out various commonly used operation or calculation.
Example:
printf() , getch() , clearscr(),
sqrt(), cos(), sin(), tolower(). toupper()
Header file:
Contains information about Library functions and must be specified in the program.
printf()  stdio.h
sqrt(), cos(), sin()  math.h
getch(), clrscr()  conio.h
tolower(), toupper()  ctype.h
CSC 202
Computer Programming
Character encoding
• Computer stores and processes data in Binary number system.
• Each character and number are given a binary sequence
To
10101001
Exam Controller,
111100110100110
Primeasia Uni.
100010000111001
Sub: …..
Stored as
11111101110111
Dear sir,
111010101010101
………..
1101001010
C:\application.doc
CSC 202
Computer Programming
Character encoding
Character & number are given a binary sequence following a
standard.
Standards are:
• American Standard Code for Information Interchange (ASCII)
• Extended Binary Coded Decimal Information (EBCDI)
• Universal Code (UniCode)
C programming Language follows ASCII.
CSC 202
Computer Programming
To
ASCII
Exam Controller,
Primeasia Uni.
• Each character is encoded in 7 bits
• 128 (27) different characters can be represented
Sub: …..
Dear sir,
………..
Character
Binary sequence
Decimal
equivalent or
ASCII value
A
B
20
1000001
1000010
0010100
65
66
20
**Full ASCII list is in the book