391 + Mcqs in Input Output Page 4 McqOptions

151.	rand() and srand() functions are used
A.	To find sqrt
B.	For and operations
C.	For or operations
D.	To generate random numbers
Answer» E.

Discussion

152.	FILE reserved word is
A.	A structure tag declared in stdio.h
B.	One of the basic datatypes in c
C.	Pointer to the structure defined in stdio.h
D.	It is a type name defined in stdio.h
Answer» E.

Discussion

153.	What is the output of this C code (when 4 and 5 are entered)?
A.	Error
B.	4 junkvalue
C.	Junkvalue 5
D.	4 5
Answer» E.

Discussion

154.	int sscanf(char string, char format, arg1, arg2, …)
A.	Scans the string according to the format in format and stores the resulting values through arg1, arg2, etc
B.	The arguments arg1,arg2 etc must be pointers
C.	Scans the string according to the format in format and stores the resulting values through arg1, arg2, etc, those arguments arg1,arg2 etc must be pointers
D.	None of the mentioned
Answer» D. None of the mentioned

Discussion

155.	Loss in precision occurs for typecasting from____________.
A.	char to short
B.	float to double
C.	long to float
D.	float to int
Answer» E.

Discussion

156.	If there is any error while opening a file, fopen will return
A.	Nothing
B.	EOF
C.
D.	Depends on compiler
Answer» D. Depends on compiler

Discussion

157.	The conversion characters d, i, o, u, and x may be preceded by h in scanf to indicate
A.	A pointer to short
B.	A pointer to long
C.	Nothing
D.	Error
Answer» B. A pointer to long

Discussion

158.	scanf returns as its value
A.	Number of successfully matched and assigned input items
B.	Nothing
C.	Number of characters properly printed
D.	Error
Answer» B. Nothing

Discussion

159.	stderr is similar to?
A.	stdin
B.	stdout
C.	Both stdout and stdin
D.	None of the mentioned
Answer» C. Both stdout and stdin

Discussion

160.	What happens when we use? fprintf(stderr, “error: could not open filen”);
A.	The diagnostic output is directly displayed in the output
B.	The diagnostic output is pipelined to the output file
C.	The line which caused error is compiled again
D.	The program is immediately aborted
Answer» B. The diagnostic output is pipelined to the output file

Discussion

161.	What happens when we use fprintf(stderr, “error: could not open filen”);
A.	The diagnostic output is directly displayed in the output
B.	The diagnostic output is pipelined to the output file
C.	The line which caused error is compiled again
D.	The program is immediately aborted
Answer» B. The diagnostic output is pipelined to the output file

Discussion

162.	What is the output of this C code if there is no error in stream fp?
A.	Compilation error
B.	0
C.	1
D.	Any nonzero value
Answer» C. 1

Discussion

163.	Within main, return expr statement is equivalent to
A.	abort(expr)
B.	exit(expr)
C.	ferror(expr)
D.	none of the mentioned
Answer» C. ferror(expr)

Discussion

164.	ftell
A.	is a function
B.	gives the current file position indicator
C.	can be used to find the size of a file
D.	All of the above
Answer» E.

Discussion

165.	stdout, stdin and stderr are
A.	File pointers
B.	File desciptors
C.	Streams
D.	Structure
Answer» B. File desciptors

Discussion

166.	In the following statement fprintf(fpt,"%n",i), the variable fpt is a/an
A.	Integer variable
B.	Arbitrarily assigned value
C.	Pointer to a file
D.	Special kind of variable called file
Answer» D. Special kind of variable called file

Discussion

167.	If a file is opened in w+ mode then
A.	after write operation reading is possible without closing and re-opening
B.	reading is possible
C.	writing is possible
D.	All of the above
Answer» E.

Discussion

168.	Predict the data type of the following mathematical operation? 2 * 9 + 3 / 2 . 0
A.	int
B.	long
C.	float
D.	double
Answer» E.

Discussion

169.	What does the statement printf("%d",10?0?5:1:12); prints :
A.	10
B.	5
C.	12
D.	1
Answer» E.

Discussion

170.	Which is true about isalnum(c), where c is an int that can be represented as an unsigned char or EOF.isalnum(c) returns?
A.	Non-zero if isalpha(c) or isdigit(c)
B.	0 if not isalpha(c) or not isdigit(c)
C.	Both Non-zero if isalpha(c) or isdigit(c) & 0 if not isalpha(c) or not isdigit(c)
D.	None of the mentioned
Answer» D. None of the mentioned

Discussion

171.	Which among the following is right?
A.	sizeof(struct stemp) > sizeof(union utemp) > sizeof(char *)
B.	sizeof(struct stemp) < sizeof(union utemp) < sizeof(char *)
C.	sizeof(struct stemp) = sizeof(union utemp) = sizeof(char *)
D.	the order Depends on the compiler
Answer» D. the order Depends on the compiler

Discussion

172.	The statement printf ("%d", ( a++) ) ; prints
A.	the current value of a
B.	the value of a + 1
C.	an error message
D.	garbage
Answer» B. the value of a + 1

Discussion

173.	Which among the following is correct function call for rand and random?
A.	rand() and random();
B.	rand() and random(1);
C.	rand(1) and random(1);
D.	rand(1) and random();
Answer» B. rand() and random(1);

Discussion

174.	fputs function writes a string to a file that only ends with a newline
A.	true
B.	false
C.	Depends on the standard
D.	Depends on the compiler
Answer» C. Depends on the standard

Discussion

175.	Find the output of the following :for (i=1,j=10;i
A.	1 1 0 2 9 3 8 4 7 5 6
B.	1 2 3 4 5 1 0 9 8 7 6
C.	1 1 1 1 1 9 9 9 9 9
D.	Infinite Loop
Answer» B. 1 2 3 4 5 1 0 9 8 7 6

Discussion

176.	int i = 5; is a statement in a C program.Which of the following are true?
A.	during execution, value of i may change but not its address
B.	during execution both the affress and value may change
C.	repeated execution may result in different addresses for i
D.	i may not have an assosiated address
Answer» D. i may not have an assosiated address

Discussion

177.	Which among the following is never possible in C when members in a structure are same as that in a union? //Let P be a structure //Let Q be a union
A.	sizeof(P) is greater than sizeof(Q)
B.	sizeof(P) is equal to sizeof(Q)
C.	sizeof(P) is less than to sizeof(Q)
D.	none of the mentioned
Answer» D. none of the mentioned

Discussion

178.	The syntax of fgets is char fgets(char line, int maxline, FILE *fp). Which is true for fgets.fgets ?
A.	returns line on success
B.	On end of file or error it returns NULL
C.	Nothing
D.	Both returns line on success & On end of file or error it returns NULL
Answer» E.

Discussion

179.	In function free(p), p is a
A.	int
B.	Pointer returned by malloc()
C.	Pointer returned by calloc()
D.	Pointer returned by malloc() & calloc()
Answer» E.

Discussion

180.	The syntax to print a % using printf statement can be done by
A.	%
B.	%%%
C.	‘%’
D.	%%
Answer» E.

Discussion

181.	Which of the following represents the function for scanf?
A.	void scanf(char *format, …)
B.	int scanf(char *format, …)
C.	char scanf(int format, …)
D.	char scanf(char format, …)
Answer» C. char scanf(int format, …)

Discussion

182.	The correct way to generate numbers between minimum and maximum(inclusive) is _________________
A.	minimum + (rand() % (maximum – minimum));
B.	minimum + (rand() % (maximum – minimum + 1));
C.	minimum * (rand() % (maximum – minimum));
D.	minimum – (rand() % (maximum+minimum));
Answer» C. minimum * (rand() % (maximum – minimum));

Discussion

183.	The sizeof(void) in a 32-bit C is_____
A.	0
B.	1
C.	2
D.	4
Answer» C. 2

Discussion

184.	Which is true about isaplpha(c), where c is an int that can be represented as an unsigned char or EOF.isalpha(c) returns?
A.	Non-zero if c is alphabetic
B.	0 if c is not alphabetic
C.	Both Non-zero if c is alphabetic & 0 if c is not alphabetic
D.	None of the mentioned
Answer» D. None of the mentioned

Discussion

185.	The first and second arguments of fopen are
A.	A character string containing the name of the file & the second argument is the mode
B.	A character string containing the name of the user & the second argument is the mode
C.	A character string containing file poniter & the second argument is the mode
D.	None of the mentioned
Answer» B. A character string containing the name of the user & the second argument is the mode

Discussion

186.	gets does the following when it reads from stdin
A.	Deletes the ‘t’
B.	Puts adds it
C.	Deletes the terminating ‘n’
D.	Nothing
Answer» D. Nothing

Discussion

187.	Which among the following mathematical function do not have a “double” return-type?
A.	srand(x);
B.	ceil(x);
C.	floor(x);
D.	both ceil(x); and floor(x);
Answer» B. ceil(x);

Discussion

188.	cos(x) returns
A.	sine of x where x is in radians
B.	sine of x where x is in degree
C.	cosine of x where x is in radians
D.	cosine of x where x is in degree
Answer» D. cosine of x where x is in degree

Discussion

189.	Which of the following operations can be performed on the file "NOTES.TXT" using the below code?FILE *fp;fp = fopen("NOTES.TXT", "r+");
A.	Reading
B.	Writing
C.	Appending
D.	Read and Write
Answer» E.

Discussion

190.	What is the meant by ‘a’ in the following operation? fp = fopen(“Random.txt”, “a”);
A.	Attach
B.	Append
C.	Apprehend
D.	Add
Answer» C. Apprehend

Discussion

191.	Printf("%d"printf("tim"));
A.	Result in a syntax error
B.	Outputs tim3
C.	Outputs garbage
D.	Prints tim and terminate abruptly
Answer» C. Outputs garbage

Discussion

192.	If a file is opened in r+ mode then
A.	reading is possible
B.	writing is possible
C.	both (a) & (b)
D.	all the above comments are true
Answer» D. all the above comments are true

Discussion

193.	The function srand(unsigned)
A.	Sets the seed for rand
B.	Doesn’t exist
C.	Is an error
D.	None of the mentioned
Answer» B. Doesn’t exist

Discussion

194.	The statement printf ("%d", ++5) ; prints
A.	5
B.	6
C.	an error message
D.	garbage
Answer» D. garbage

Discussion

195.	Which of the following statements are FALSE about the below code?int main(int ac, char *av[]){}
A.	ac contains count of arguments supplied at command-line
B.	av[] contains addresses of arguments supplied at a command line
C.	In place of ac and av, argc and argv should be used.
D.	The variables ac and av are always local to main()
Answer» D. The variables ac and av are always local to main()

Discussion

196.	The fseek function
A.	needs 3 arguments
B.	makes the rewind function unnecessary
C.	is meant for checking whether a given file exists or not
D.	both (a) and (b)
Answer» E.

Discussion

197.	printf( "%c", 100);
A.	prints 100
B.	prints ASCII equivalent of 100
C.	prints garbage
D.	none of above
Answer» C. prints garbage

Discussion

198.	FILE is of type ______
A.	int type
B.	char * type
C.	struct type
D.	None of the mentioned
Answer» D. None of the mentioned

Discussion

199.	What is the purpose of "rb" in fopen() function used below in the code?FILE *fp;fp = fopen("source.txt", "rb");
A.	open "source.txt" in binary mode for reading
B.	open "source.txt" in binary mode for reading and writing
C.	Create a new file "source.txt" for reading and writing
D.	None of above
Answer» B. open "source.txt" in binary mode for reading and writing

Discussion

200.	Escape sequences are prefixed with
A.	%
B.	/
C.	”
D.	None of the mentioned
Answer» E.

Discussion

Explore topic-wise MCQs in C Programming.

rand() and srand() functions are used

FILE reserved word is

What is the output of this C code (when 4 and 5 are entered)?

int sscanf(char *string, char *format, arg1, arg2, …)

Loss in precision occurs for typecasting from____________.

If there is any error while opening a file, fopen will return

The conversion characters d, i, o, u, and x may be preceded by h in scanf to indicate

scanf returns as its value

stderr is similar to?

What happens when we use? fprintf(stderr, “error: could not open filen”);

What happens when we use fprintf(stderr, “error: could not open filen”);

What is the output of this C code if there is no error in stream fp?

Within main, return expr statement is equivalent to

ftell

stdout, stdin and stderr are

In the following statement fprintf(fpt,"%n",i), the variable fpt is a/an

If a file is opened in w+ mode then

Predict the data type of the following mathematical operation? 2 * 9 + 3 / 2 . 0

What does the statement printf("%d",10?0?5:1:12); prints :

Which is true about isalnum(c), where c is an int that can be represented as an unsigned char or EOF.isalnum(c) returns?

Which among the following is right?

The statement printf ("%d", ( a++) ) ; prints

Which among the following is correct function call for rand and random?

fputs function writes a string to a file that only ends with a newline

Find the output of the following :for (i=1,j=10;i

int i = 5; is a statement in a C program.Which of the following are true?

Which among the following is never possible in C when members in a structure are same as that in a union? //Let P be a structure //Let Q be a union

The syntax of fgets is char *fgets(char *line, int maxline, FILE *fp). Which is true for fgets.fgets ?

In function free(p), p is a

The syntax to print a % using printf statement can be done by

Which of the following represents the function for scanf?

The correct way to generate numbers between minimum and maximum(inclusive) is _________________

The sizeof(void) in a 32-bit C is_____

Which is true about isaplpha(c), where c is an int that can be represented as an unsigned char or EOF.isalpha(c) returns?

The first and second arguments of fopen are

gets does the following when it reads from stdin

Which among the following mathematical function do not have a “double” return-type?

cos(x) returns

Which of the following operations can be performed on the file "NOTES.TXT" using the below code?FILE *fp;fp = fopen("NOTES.TXT", "r+");

What is the meant by ‘a’ in the following operation? fp = fopen(“Random.txt”, “a”);

Printf("%d"printf("tim"));

If a file is opened in r+ mode then

The function srand(unsigned)

The statement printf ("%d", ++5) ; prints

Which of the following statements are FALSE about the below code?int main(int ac, char *av[]){}

The fseek function

printf( "%c", 100);

FILE is of type ______

What is the purpose of "rb" in fopen() function used below in the code?FILE *fp;fp = fopen("source.txt", "rb");

Escape sequences are prefixed with

int sscanf(char string, char format, arg1, arg2, …)

The syntax of fgets is char fgets(char line, int maxline, FILE *fp). Which is true for fgets.fgets ?