Basic

C  Language  में Program को लिखने का तरीका :

int main()
{

return 0 ;
}

C  language में program लिखने के लिए सबसे पहले main() function  लिखा जाता है |  main () फंक्शन लिखना अनिवार्य होता है , क्योकि program execution main () से ही होता है | 

और last में return 0  लिखा जाता है|  return  0 main () function  में 0 integer value value return करता है |  

Data Type 

c  program  में data value  स्टोर करने के लिए पहले data type को  define करना होता है | data type को define  करने से machine को ये समझ में आ जाता है की user को अपने program  को run कराने के लिए कितनी memory की जरुरत है , तथा किस प्रकार की value उस memory में store होगी |  

different type की value store करने के लिए , different type के data type available  है | 

data type , 2 प्रकार के होते है :- 
a) primary data type 
b ) User define data type  


a) primary data type
Primary data type c compiler में पहले से ही define रहते है | 

1. char  (1 byte )
2. int  (2  byte )
3. float  (4  byte )
4. double (8 byte )
5. void   

b ) User define data type  

ये data type user द्वारा define किये जाते है :-
1. Array
2. Structure
3. Union
4. Pointer
5 Enum etc

Scalar Data Type

Scalar data type में एक variable में एक समय में एक ही value store  होती है | जैसे :-
1. arithmetic 
a Integer 

b Float 

2. Pointer 

3. Enum 

Format specifier 

different type के data type की value store और output value present कराने के लिए data type से related , format specifier का use किया जाता है | जैसे :-

1. int -> "%d "
2. float->%f 
3 double->%lf
4 char ->%c
5 string ->%s 

Token :

program में लिखी गई प्रत्येक individual unit token कहलाती है |

Token  6 प्रकार के होते है | 

1 keyword 

2 Identifier 

3 constant 

4 string 

5 special symbol ({},())

6 Operator (+,-)

Identifier in  C 

C  program में जिनकी किसी न किसी नाम के द्वारा एक निजी पहचान  होती है  , उन्हें C program  में identifier कहते है |
जैसे की variable name , function name , array name | 

Identifier  लिखने के नियम :- 

1. identifier लिखते समय आप character (a to z ,A  to Z ) और digit (0  to  9 ) का use कर सकते हो |  

2. identifier लिखते समय पहला letter character  ही होगा | 

3. underscore (_) के अलावा कोई दूसरा special symbol का use नहीं किया जाता है | 

4. keyword का use नहीं कर सकते | 

5 दो identifier के नाम कभी भी एक जैसे नहीं हनी चाइये | 

Keyword

C  Compiler में 32 प्रकार के Keyword use किये जाते है | 

1. auto 
2. break 
3. case 
4. const 
5. char 
6. continue 
7. default 
8. do 
9. double 
10. else 
11. enum 
12. extern 
13. float 
14. for 
15. goto 
16. if 
17. int 
18. long 
19. register 
20. return 
21. short 
22. signed 
23. size of 
24. static 
25. struct 
26. switch
27. typedef 
28. union  
29. unsigned
30. volatile 
31. void 
32. while 

Console Input /output 

Console Input /Output  दो प्रकार क होते है |
1. Formatted Input /Output
2. Unformutted Input /Output

1. Formatted Input /Output 

Formatted Function
Type	Input	Output
Char	Scanf()	Printf()
Int,float,string	Scanf()	Printf()

Use printf () and scanf ()

#include<stdio.h>
#include<conio.h>
int main()
{
char d[30];
printf("enter any character\n");
scanf("%s",d);
printf("%s",d);
gets(d);
puts(d);

}

2. Unformutted Input /Output

UnFormatted Function
Type	Input	Output
Char	getch() getche() getchar()	Putch() Putchar()
string	gets()	Puts()

getchar () and putchar()

#include<stdio.h>
int main()
{
char d;
d=getchar();
putchar(d);

}

getche ()

putchar() , putch() की तरह  putche () function का use नहीं किया जाता |

#include<stdio.h>
#include<conio.h>
int main()
{
char d;
puts("enter any character\n");
d=getche();
puts("\nthe output is " );
putch( d);
}

gets () and  puts ()

#include<stdio.h>
#include<conio.h>
int main()
{
char d[30];
puts("enter any character\n");
gets(d);
puts(d);

}

Program:

Octal Constant:

 #include<stdio.h>
int main()
{
  int a=013;
  printf("%d",a);

return 0;

}

Output:11


Hexadecimal Constant:

 #include<stdio.h>
int main()
{
  int a=0x13;
  printf("%d",a);

return 0;

}

Output:19

Macros 

#include<stdio.h>

#include<conio.h>

#define AB 10

int main()

{

printf("%d",AB);

#undef AB

printf("hii");

 printf("%d",AB);

}

printf("%d",AB); line में error आएगी क्योकि  AB को undefine कर दिआ गया है | 

Type Conversion

Type Conversion दो प्रकार क होते है :-
जब different प्रकार के data type  को operate किया जाता है, तब type conversion का use  होता है | 
(जैसे :- 2 +4. 5 )  यहाँ पे 2 integer type है , पर 4. 5 real type है | 
1. Implicitly 
2. Explicitly 

1. Implicitly 

Implicitly type conversion  में compiler automatic ही data के type को convert करता है | 

यदि दो different प्रकार के data type  है तो compiler automatic ही answer को बढ़े data type में convert कर देता है , इसी को implicit conversion कहते है | 


example:
#include<stdio.h>
#include<stdlib.h>
int main()
{
int a=100,x;
char b='B';
x=a+b;


printf("%d",x);

float j=2.5;
j=x +j;
printf("\n%f",j);
}

Output:
166
168.50000

Explicitly 
जब user different प्रकार के data type का use करता है तब implicitly conversion द्वारा compiler अपने आप ही result को बढ़े data type के अनुसार change कर देता है |

पर यदि user अपने अनुसार data convert करना चाहता है तब आपको explicit type conversion का use किया जाता है |

for example :
#include<stdio.h>
#include<stdlib.h>
int main()
{
float a=2.5;
int b=1,c;
c=(int)a+b;
printf("%d",c);


}
Output :
3


Ctype in C

Ctype.h , c compiler  की library में मौजूद एक header file  है | जिसके अंदर isalpha () ,isalnum () जैसे  function शामील है , जिनका use pass किये गए character क बारे में जानकारी देने के लिए होता है | न
जैसे :-

1. #include<stdio.h>
#include<ctype.h>
int main()
{
int a= '5';
if isalnum(a)
printf("this is numeric value");
else
printf("not numeric value");
}

Output:

this is numeric value

2. #include<ctype.h>
int main()
{
int a= '6' ,b='\t',c='y';
if isalpha(a)
printf("\n  this is numeric value");
else
printf("\n not numeric value");

if isalpha(b)
printf("\n this is numeric value");
else
printf("\n not numeric value");

if isalpha(c)
printf("\n this is numeric value");
else
printf("\n not numeric value");
}

Output:

not numeric value

not numeric value

this is numeric value

Print exact character

#include<stdio.h>
int main()
{
int b=4;
  char a[20]="abcdefghi";
  printf("%.5s",a);
  printf("\n%.*s",b,a);


}

MCQ:

1  The keyword used to transfer control from a function back to the calling function is

A) switch

B) goto

C) go back

D) return

2  Which of the following cannot be used as identifiers?

A) Spaces

B) Digits

C) Underscores

D) Letters

3. In the passage of text, individual words and punctuation marks are known as

A) Constants

B) Keywords

C) Operators

D) Tokens

4  Choose the option that contains only valid hexadecimal integers.

A) 0x9F, 0xbcd, 0x1

B) 037, 0xx, 01000

C) 0x561u, 0x9h, 0xdd

D) H9F, HFF, HAA

5  Which one of the following are not valid variable names in C?

A) float_int, keyword, A1

B) ANSI, ascii, cpu

C) valid, variable, name

D) None of the above

 6 Which of the following is a valid identifier?

 A) 1return

 B) return1

 C) return

 D) $return_1

7  Which of the following is a valid string constant?

    A)  “programming” 

    B)   “programming

     C) ‘programming

         D) $ programming $

8  Which of the following language is predecessor to ‘C’ Programming Language?

         A)  A  
         B) B

    C) ADA

    D) C++

9 Which of the following a not a basic data type used in C language?

 A) double

 B) float

 C) char

 D) array

10  Which is an incorrect variable name?

A) Id_No

 B) ID_NO

 C) IdNo

D) Id No

11 By default a real number is treated as a

 A) float

B) double

C) long double

D) integer

12  ‘C’ Programming Language was developed and written by

A) Martin Richards

B) Dennis Ritchie

C) Ken Thompson

 D) Herman Hellorith

13  Which of the following is false in ‘C’ Programming Language

 A) Keywords can be used as variable names

 B) Variable names can contain digits

 C) Variable names do not contain blank spaces

D) Capital letters can be used in variable names.

14  By default a real number is treated as a

A)  Float

B)   double

C)   long double

D)   integer

15  What will be the output of the following program? 
main()
 { 
int a; printf(“%d”,a);
 }

A) 0

B) 1

C) Error

D) Unpredictable Value

16  Suppose that x is initialized as: short int x; /* assume x is 16 bits in size */ What is the maximum number that can be printed using

printf (“%d\n”, x),

 A) 127

B) 128

C) 255

D) 32,767

55 Which of the following directive creates functions like macros?

 A) #include

 B) #define

C) #undef

D) #ifdef

56 Which format specification is used in printf statement to print hexadecimal format

 A) %i

 B) %c

 C) %x

 D) %u

57 size of operator returns the size in bytes of

A) identifier

B) type

C) identifier or type

 D) array

59 Which of the following is a valid octal constant?

 A) 32

B) 032

 C) 049

D) 0x49

60 What will be the output of the following?

main()

{

int a = ‘A’;

 printf(“%d”, a);

A) 65

B) A

C) a

D) the program will not compile as an integer variable is assigned a character constant.

61. Which one is incorrect statement for C Language?

A) C compiler supports octal integer constant.

B) C compiler supports hexadecimal integer constant.

C) C compiler supports binary integer constant.

D) C compiler supports decimal integer constant.

62. What will be the output of the following code?

int main()

 {

 int x,y,z;

 x='1'-'0'; /* line-1 */

y='a'-'b'; /* line-2 */

z=x+y;

printf("%d",z); }

 A) 0

 B) Error because of incorrect line-1 only.

 C) Error because of incorrect line-1 and line-2.

 D) Error because of incorrect line-2 only.

63. Which of the following cannot be used as identifiers?

A) spaces

B) digits

C) underscores

D) letters

65. Identify the correct sequence of steps to run a program

A) Link, Load, Code, Compile & Execute

B) Code, Compile, Link, Execute & Load

C) Code, Compile, Link, Load & Execute

D) Compile, Code, Link, Load & Execute

67. What will be the output of following program

 #include main()

{

int x,y = 10;

x = y * NULL;

printf(“\n %d \n", x);

}

A) error

B) 0

C) 10

D) Garbage value

3  Function of a compiler is to

A) put together the file and functions that are required by the program

B) translate the instructions into a form suitable for execution by the program

C) load the executable code into the memory and execute them

D) allow the user to type the program

4. find output
int x = 7538;

 printf("%d %d\n", x % 100, x / 10);

True/False

1. All of the following are expressions in c.

               i.      A=2+(b=5);

              ii.      A=b=c=5;

            iii.      A=11%3;

2 .  Expression if a(=6).

3 .  A variable is a string that varies during program execution.

4 .  C language cannot be used for database manipulation.

5 .  In the expression a=b=5 the order of assignment is not decided by associativity of operators.

6 .  A printf statement can be used to display output on different lines.

7.   # is used to insert comments in the program.

   ->       Calling a uninitialized variable will provide zero value.

8.           #define is known as preprocessor compiler directive.

9.           Sizes of short integer and long integer would vary from one platform to another.

10.           If we have to execute the program with different set of inputs, we need to recompile the program each time.

11.            Compiler translates the of source code into object code before the program can be executed.

12.     The programming language happens to be the high level language with some assembly language features.

13.           In C the graphics may be used to add graphical features to the program.

14.           Every variable in c have three most fundamental attributes: Name, Value, Address.

        The operating system converts the ‘C’ program into machine language.

15.           Every function in ‘C’ must have a “return” statement.

16.           C is an object oriented programming language.

17.           Sizes of short integer and long integer would vary from one platform to another.

     A preprocessor directive is a message from compiler to the linker.

18.           cout and cin can be used for output and input respectively in ‘C’ language.

19.           In computer programming, the translation of source code into object code is done by a compiler.

20.           Scalar data types are not supported by ‘C’ language.

21.           ‘C’ programs are converted into machine language with the help of an interpreter.

22.             Every ‘C’ program must contain a main( ).

23.            Putchar( ) is used only for single character input

24.           36 A printf( ) statement can generate only one line of output.

25.            The #undef directive removes a name previously defined with #define directive

26.     

27.           In ‘C’, unsigned int can have maximum range of values between 0 to 65535.

28.           An escape sequence begins with a backward slash followed by an alphabetical character

29.           NULL is a keyword in C.

30.           1.0 is an example of double constant and float constant.

31.           #define is used to define symbolic constant.

32.           const is a keyword that is used to define symbolic constant.

33.            A double data type number uses 64 bits giving a precision of 14 digits. 

34.            Every C program must have at least one main ( ) function section.

35.           Is the following statement valid in C? int my_num=100,000;

36.           We need to recompile the program before executing it even if there is no change in the source code.

37  The default precision for printing of floating point values is 6. If the floating-point number is more precise than 6 digits, it will be rounded. 
38  int main()
{
int a;
scanf("%c",&a);
printf("%c",a);

return 0;
}
is their any error in above code.


39.There is no difference between '\0' and '0'.

40.Comments in the program make debugging of the program easier

41. The statement void p; is valid.

42.  An algorithm is a graphical representation of the logic of a program.

43.Calling a uninitialized variable will provide zero value.

44. Linking is the process of putting together other program file and functions that are required by the program

45.  Algorithm is the graphical representation of logic.

46. 20.    The programming language happens to be the high level language with some assembly language features.

47.   A preprocessor directive is a message from compiler to the linker.

48.  cout and cin can be used for output and input respectively in ‘C’ language.
     
     49.  In computer programming, the translation of source code into object code is done by a compile

Match the following

(A)

1.	Smallest individual unit in a program is known as	A	integer
2.	“2 “ is known as	B	4
3.	Control string required to print long int	C	ceil
4.	Default return type in any function is	D	String Constant
5.	Logical not operator is	E	%ld
6.	Size of long int n byte	F	C Tokens
7.	Terminates program	G	Unary
8.	Explicit conversion	H	main()
9.	Unary operator	I	three
10.	Number of operators required in ?: operator	J	/*
11.	To insert the comments in the program this symbol is used	K	exit()
12.	Size of float and double in bytes	L	Typecasting
13.	Round off a value 1.66 to 2.0	M	++
14.	Input/output function prototypes and macros are defined in	N	header
15.	This is a mandatory function in every ‘C’ program. Execution starts from this function	O	4,8

(B)

18.	Preprocessor commands are also known as	A	Converts a data type to another data type
19.	Formatted print is used to	B	Stdio.h
20	exit(0) in a ‘C’ program represents	C	‘a’ is a single character constant and “a” is a string character constant
21	Typecasting	D	directives
22	The difference in ‘a’ and “a” is	E	!
23		F	Take printout in special format
24	The operator && is an example of	G	directives
25	Header files in ‘C’ contain	H	#
26		I	logical
27	Preprocessor commands are always preceded by	J	main()
28	The bitwise AND operator is used for	K	\0
29	exit( ) function is used to terminate the	L	b=a
30	Null character is represented by	M	Library functions
18.	Preprocessor commands are also known as	N	Take printout in special format
19.	Formatted print is used to	O	Program
		P	Termination of a program
		Q	masking

(c)

31	Operator for giving remainder	g	Binary file
32		h	masking
33	assignment of a with b	i	a^=b^=a^=b
34	Which is not possible in C?	j	program
35	Which is not portable?	k	%
36	Compiler converts a source File to	l	Static variable
37	Reserved word	m	?:
38	Swap a and b without temporary variable	n	Header File
39		o	Typecasting
40	A sequence of bytes flowing into or out of program	p	keyword
41	An operator expressed in three part expression	q	Object file
42	An external source file that contains declarations and definitions.	r	a=b
43	Converting to a different data type	s	stream
44	Pictorial representation of logic	t	#define
45	Defining constants	u	Declaration
46	Space allocation to variables	v	nothing
		w	Pictorial representation of logic

Question:

1.   Define void data type

2.   In the following declaration statement: char c=’A’; Variable c stores one byte of memory space while character constants ‘A’ stores one byte memory space. How one byte variables can stores two byte character constant? What is automatic type promotion in c?

3.   What are preprocessor directions? Why do we need them? Explain various preprocessor directives?

4. How Compilation, Linking and Loading are related? Also explain the basic task of a Compiler, Linker and Loader?

5.           Distinguish between compiler error and runtime error with the help of an example

6.           What is a preprocessor and what are the advantages of preprocessor? What are the facilities provided by preprocessor?

7.           What is meant by formatted output? Mention the output of the following commands. int n = 28; i) printf ( “% 5d,”n); ii) printf ( “%+5d”, n); iii) printf ( “%+5d”, n);

8.   What is the significance of header file in a C Program? What do the header files usually contain?

9. How Compilation, Linking and Loading are related? Also explain the  basic task of a Compiler, Linker and Loader.

         

10.     List out the rules to declare a valid variable in ‘C’ program.

11.  WAP for swaping two variable 

12.  What are the commonly used input functions in ‘C’? Write their syntax and explain the purpose of each.

13.  What are logical, syntactic and execution errors? Give examples of each. Which is most difficult to find and why

14.  Enumerate features of a good ‘C’ program. Describe the commonly used techniques as to how ‘C’ programs can be made highly readable and modifiable.

15.  What is an algorithm?

16.  ‘C’ compiler supports many pre-processor commands. Write their names only.

17 What is an execution error? Differentiate it from syntactic error. Give examples

18  It is said that ‘C’ is a middle level assembly language. Mention those features of ‘C’ which enable this description.

19 It is said that “C is a middle level language and is good for system level programming.” Describe three facilities available in ‘C’ which support this statement.

20. What do you understand by loading and linking of a program?

21. Explain the role of linker and loader in compilation.

23. Write a ‘C’ program to swap two variables without using third variable.

24. Write a ‘C’ program in which a scanf() function can read a complete paragraph of text.

25. How can you create your own header file in ‘C’ programming? Briefly explain.

26 #include<stdio.h>

int main()

{

char d;

d=getchar();

putchar(d);

}

If You  enter input  as "C Programming " then  what output has to  be shown 

27 #include<stdio.h>
#include<conio.h>
int main()
{
char d;
puts("enter any character\n");
gets(d);
puts(d);

}

is this program इस true  और not

28.  What is void data type? Write any three use of void data type.

29.  Explain the working of shorthand assignment operators, pre and post increment operator and the ternary operator.

30.  Differentiate declaration and definition of a variable.

31. 34 What is meant by formatted output? Mention the output of the following commands.

 int n = 28; i) printf ( “% 5d,”n); ii) printf ( “%+5d”, n); iii) printf ( “%+5d”, n);

32. output:

#include<stdio.h>
#include<stdlib.h>
int main()
{
int a=10;
printf("hello");
exit(0);
printf("heelo2");
}

19 What is meant by formatted output? Mention the output of the following commands.

 int n = 28;

 i) printf ( “% 5d,”n);

 ii) printf ( “%+5d”, n);

 iii) printf ( “%+5d”, n);