C LECTURE02

8/7/2019 C LECTURE02

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Constants, Variables

and Datatypes


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Trigraph SequencesTrigraph Sequence Translation??= # number sign

??( [ left bracket

??) ] right bracket

??< { left brace

??> } right brace

??! | vertical bar

??/ \ back slash

?? ^ caret

??- ~ tilde


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C Tokensy keywords : float, for, while

y identifiers : amount num

y Constants : -15.5 100

y strings : ABC Hello 5

y operators : + > < * -

y special Symbols :[ ] { } ( ) $


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Keywords and Identifiers

y Keyword :

meaning ofwordis known to compiler

y Identifier :

name given by user to variable, function .


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Keywordsauto double int struct

break else long switch

case enum register typedef

char extern return unionconst float short unsigned

continue for signed void

default goto sizeof volatile

do if static while


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Identifiersy Identifiers refer to the names of variables, functions and arrays.

y Permissible character for naming :

alphabet a-z, A-Z

underscore _

digit 0,1,2..9

Rules for identifiers :

1. First character must be an alphabet (or underscore).2. Must consist of only letters, digits or underscore.

3. Only first 31 characters are significant.

4. Cannot use a keyword.

5. Must not contain white space.


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ConstantConstant

Primary

Numeric Character

Integer Real ingle ing

constants constants character consta

constants


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Integer Constanty Sequence of digits

Integer Constant

digits 0,1,..9 digits o,1,.7

A..F/af

Ex., 123

-321

+78

0

Decimal Integer Octal IntegerHexadecimal

Integer


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Integer Constants16-bit m/c : -32768 to +32767

32-bit m/c : -2147483648 to +2147483647

56789U or 56789u

987612347UL or 987612347ul (unsigne

9876543L or 9876543l


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Real Constanty Numbers containing fractional part

Real Constant

Ex., 0.0083

-0.75

435.36

+247.0

-.71

.95

Decimal NotationExponential(Scientific)

notation

mantissa e exponent


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Example of Numeric Constant698354L

25,000

+5.0E3

3.5e-57.1e 4

-4.5e-2

1.5E+2.5

$255

0X7B


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Single Character Constantsy Single character enclosed within a pair of single quote

marks.

y Ex.,

X ; 5

y Character constant has integer value, i.e., ASCII value.

printf(%d, a);

printf(%c, 97);

y Arithmetic operation can be performed using characterconstant.


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String Constantsy Sequence of characters enclosed within a pair of double

quote marks.

y

Ex.,Hello X ?---!

6587 Have a nice day


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Backslash Character Constant/

Escape SequenceConstant Meaning

\a Audible

\b Back space

\f Form feed

\n New line\r Carriage return

\t Horizontal tab

\v Vertical tab

\ Single quote

\ Double quote

\? Question mark

\\ Backslash

\0 Null


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DatatypesDatatypes

Primary/Fundamental /PrimitveData types

User-definedData types

DerivedData types

Integer

Character

Float

Double

Array

Pointer

Function

Structure

Union

Enum


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Datatypes


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Size and Range of Data Types on a 16-bit Machine

Type Size(Bits) Range

char / signed char 8 -128 to +127 %c

unsigned char 8 0 to 255 %c

int / signed int 16 -32,768 to 32,767 %d

unsigned int 16 0 to 65535 %ushort int / signed short int 8 -128 to 127 %d

unsigned short int 8 0 to 255 %u

long int / signed long int 32 -2,147,483,648 to 2,147,483,647 %ld

unsigned long int 32 0 to 4,294,967,295 %lu

float 32 3.4E-38 to 3.4E+38 %f

double 64 1.7E-308 to 1.7E+308 %lf

long double 80 3.4E-4932 to 1.1E+4932 %Lf


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Operators & Expression

Operators

Arithmeticoperator

Bitwiseoperators

Relationaloperator

Logicaloperator

Assign-ment

operator

Increment&

Decrement

Condi-tional

operator

Specialoperators

+-

*/%

&&

||! =

++

-- ?:

&|

>

,sizeof

* &. ->

===!=


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Defining Member Functions :

Inside the Class Definitiony Replace the function declaration by the actual function definition

inside the class.class item{

int number;

float cost;

public :void getdata(int a, float b);

void putdata(void){

cout


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Defining Member Functions :

Inside the Class Definitiony When a function is defined inside a class, it is treated as an

inline function.

Therefore, all the restrictions and limitations that apply to aninline function are also applicable here.

y Normally, only small functions are defined inside the classdefinition.


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#include #include

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C LECTURE02