Input / Output - C Programming Questions and Answers - RejinpaulPlacement

Answer & Solution

Answer: (C) "I am a boy\n\0"
Solution:
Declaration: char *fgets(char *s, int n, FILE *stream);

fgets reads characters from stream into the string s. It stops when it reads either n - 1 characters or a newline character, whichever comes first.

Therefore, the string str contain "I am a boy\n\0"

2.

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 and writing

B.

Create a new file "source.txt" for reading and writing

C.

open "source.txt" in binary mode for reading

D.

None of above

Answer & Solution

Answer: (C) open "source.txt" in binary mode for reading
Solution:
The file source.txt will be opened in the binary mode.

3.

What does fp point to in the program ?

#include
int main()
{
FILE *fp;
fp=fopen("trial", "r");
return 0;
}

A.

The first character in the file

B.

A structure which contains a char pointer which points to the first character of a file.

C.

The name of the file.

D.

The last character in the file.

Answer & Solution

Answer: (B) A structure which contains a char pointer which points to the first character of a file.
Solution:
The fp is a structure which contains a char pointer which points to the first character of a file.

4.

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 & Solution

Answer: (D) Read and Write
Solution:
r+ Open an existing file for update (reading and writing).

5.

To print out a and b given below, which of the following printf() statement will you use?

#include
float a=3.14;
double b=3.14;

A.

printf("%f %Lf", a, b);

B.

printf("%Lf %f", a, b);

C.

printf("%Lf %Lf", a, b);

D.

printf("%f %lf", a, b);