Discussion
Home ‣ C Programming ‣ Input / Output Comments
- Question
To print out a and b given below, which of the following printf() statement will you use?
#include<stdio.h> float a=3.14; double b=3.14;
Options- A. printf("%f %lf", a, b);
- B. printf("%Lf %f", a, b);
- C. printf("%Lf %Lf", a, b);
- D. printf("%f %Lf", a, b);
- Correct Answer
- printf("%f %lf", a, b);
ExplanationTo print a float value, %f is used as format specifier.To print a double value, %lf is used as format specifier.
Therefore, the answer is printf("%f %lf", a, b);
Input / Output problems
Search Results
- 1. Out of fgets() and gets() which function is safe to use?
Options- A. gets()
- B. fgets() Discuss
Correct Answer: fgets()
Explanation:
Because, In fgets() we can specify the size of the buffer into which the string supplied will be stored.- 2. To scan a and b given below, which of the following scanf() statement will you use?
#include<stdio.h> float a; double b;
Options- A. scanf("%f %f", &a, &b);
- B. scanf("%Lf %Lf", &a, &b);
- C. scanf("%f %Lf", &a, &b);
- D. scanf("%f %lf", &a, &b); Discuss
Correct Answer: scanf("%f %lf", &a, &b);
Explanation:
To scan a float value, %f is used as format specifier.To scan a double value, %lf is used as format specifier.
Therefore, the answer is scanf("%f %lf", &a, &b);
- 3. Which of the following function is more appropriate for reading in a multi-word string?
Options- A. printf();
- B. scanf();
- C. gets();
- D. puts(); Discuss
Correct Answer: gets();
Explanation:
gets(); collects a string of characters terminated by a new line from the standard input stream stdin#include <stdio.h> int main(void) { char string[80]; printf("Enter a string:"); gets(string); printf("The string input was: %s\n", string); return 0; }Output:
Enter a string: CuriousTab
The string input was: CuriousTab
- 4. Which of the following function is correct that finds the length of a string?
Options- A.
int xstrlen(char *s) { int length=0; while(*s!='\0') { length++; s++; } return (length); } - B.
int xstrlen(char s) { int length=0; while(*s!='\0') length++; s++; return (length); } - C.
int xstrlen(char *s) { int length=0; while(*s!='\0') length++; return (length); } - D.
int xstrlen(char *s) { int length=0; while(*s!='\0') s++; return (length); }
Discuss
Correct Answer:int xstrlen(char *s) { int length=0; while(*s!='\0') { length++; s++; } return (length); }
Explanation:
Option A is the correct function to find the length of given string.Example:
#include<stdio.h> int xstrlen(char *s) { int length=0; while(*s!='\0') { length++; s++; } return (length); } int main() { char d[] = "CuriousTab"; printf("Length = %d\n", xstrlen(d)); return 0; }Output: Length = 8
- 5. If the two strings are identical, then strcmp() function returns
Options- A. -1
- B. 1
- C. 0
- D. Yes Discuss
Correct Answer: 0
Explanation:
Declaration: strcmp(const char *s1, const char*s2);The strcmp return an int value that is
if s1 < s2 returns a value < 0
if s1 == s2 returns 0
if s1 > s2 returns a value > 0
- 6. In a file contains the line "I am a boy\r\n" then on reading this line into the array str using fgets(). What will str contain?
Options- A. "I am a boy\r\n\0"
- B. "I am a boy\r\0"
- C. "I am a boy\n\0"
- D. "I am a boy" Discuss
Correct Answer: "I am a boy\n\0"
Explanation:
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"
- 7. Which files will get closed through the fclose() in the following program?
#include<stdio.h> int main() { FILE *fs, *ft, *fp; fp = fopen("A.C", "r"); fs = fopen("B.C", "r"); ft = fopen("C.C", "r"); fclose(fp, fs, ft); return 0; }
Options- A. "A.C" "B.C" "C.C"
- B. "B.C" "C.C"
- C. "A.C"
- D. Error in fclose() Discuss
Correct Answer: Error in fclose()
Explanation:
Extra parameter in call to fclose().- 8. What is the purpose of "rb" in fopen() function used below in the code?
FILE *fp; fp = fopen("source.txt", "rb");
Options- 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 Discuss
Correct Answer: open "source.txt" in binary mode for reading
Explanation:
The file source.txt will be opened in the binary mode.- 9. Consider the following program and what will be content of t?
#include<stdio.h> int main() { FILE *fp; int t; fp = fopen("DUMMY.C", "w"); t = fileno(fp); printf("%d\n", t); return 0; }
Options- A. size of "DUMMY.C" file
- B. The handle associated with "DUMMY.C" file
- C. Garbage value
- D. Error in fileno() Discuss
Correct Answer: The handle associated with "DUMMY.C" file
Explanation:
fp = fopen("DUMMY.C", "w"); A file DUMMY.C is opened in write mode and returns the file pointer to fpt = fileno(fp); returns the handle for the fp stream and it stored in the variable t
printf("%d\n", t); It prints the handle number.
- 10. What does fp point to in the program?
#include<stdio.h> int main() { FILE *fp; fp=fopen("trial", "r"); return 0; }
Options- 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. Discuss
Correct Answer: A structure which contains a char pointer which points to the first character of a file.
Explanation:
The fp is a structure which contains a char pointer which points to the first character of a file.
Comments
There are no comments.
More in C Programming:
Programming
Copyright ©CuriousTab. All rights reserved.