Quiz for File operations fscanf

Q1: What is the primary purpose of fscanf()?

A. To read formatted input from a file B. To write formatted output to a file C. To open a file D. To close a file

Q2: Which header file declares fscanf()?

A. <stdio.h> B. <stdlib.h> C. <string.h> D. <fcntl.h>

Q3: What does fscanf(fp, "%d", &num) do?

A. Reads an integer from the file pointed by fp into num B. Writes integer num to file C. Closes the file D. Formats integer but does not read

Q4: What is the return value of fscanf() on successful reads?

A. Number of input items successfully matched and assigned B. 0 C. -1 D. EOF

Q5: Can fscanf() read strings from a file?

A. Yes, using format specifier %s B. No, only numbers C. Only characters D. Only binary data

Q6: What happens if fscanf() fails to read?

A. Returns EOF or a number less than expected B. Returns zero C. Throws exception D. Program terminates

Q7: Which of these is a valid fscanf() usage?

A. fscanf(fp, "%s", str) B. fscanf("%s", fp, str) C. fscanf(str, "%s", fp) D. fscanf(fp, str, "%s")

Q8: Can fscanf() read multiple variables in one call?

A. Yes, using multiple format specifiers B. No, only one variable at a time C. Only strings D. Only integers

Q9: Which format specifier reads a floating point number?

A. %f B. %d C. %c D. %s

Q10: Is fscanf() type-safe?

A. No, incorrect format specifiers lead to undefined behavior B. Yes, always safe C. Compiler checks all formats D. Errors are caught at runtime

Q11: What must be done before using fscanf()?

A. File must be opened with fopen() B. File must be closed C. File pointer must be NULL D. File must be created manually

Q12: Can fscanf() read binary data?

A. No, it reads formatted text only B. Yes, always C. Only if format is %b D. Depends on compiler

Q13: Can fscanf() be used to read from stdin?

A. Yes, by passing stdin as the file pointer B. No, only files C. Only with file pointers D. Only for strings

Q14: Does fscanf() skip whitespace automatically?

A. Yes, except for %c and %[ specifiers B. No, never C. Only with %d D. Only with %s

Q15: What is the correct way to read a single character with fscanf()?

A. fscanf(fp, "%c", &ch) B. fscanf(fp, "%s", &ch) C. fscanf(fp, "%d", &ch) D. fscanf(fp, "%f", &ch)

Q16: Is it necessary to check the return value of fscanf()?

A. Yes, to ensure data was read correctly B. No, always successful C. Only when reading numbers D. Only for strings

Q17: Which argument is mandatory for fscanf()?

A. FILE * stream B. Format string only C. Variable arguments only D. None

Q18: Can fscanf() read input until newline?

A. No, stops at first whitespace unless specified B. Yes, always C. Only with %[^ ] D. Only with %c

Q19: Does fscanf() modify the file pointer position?

A. Yes, advances as data is read B. No, file pointer is static C. Only on error D. Only when reading text

Q20: Can fscanf() cause buffer overflow?

A. Yes, if input data is larger than buffer B. No, always safe C. Only on Linux D. Only on Windows