C Programming Language Mcq Exercise 2

• ✅ The input string is not null-terminated.
• ✅ Causes buffer overflow vulnerabilities.
• ✅ Can only read a predetermined number of characters.

Explanation:

Option c is the correct answer. It can cause buffer overflow because the gets method will not check the limits of the input buffer.

1. Which of the following options describes the functions of the setjmp and longjmp functions in C?

• ✅ Longjmp sets its destination with setjmp and creates a non-local goto.
• ✅ Longjmp sets the destination, and setjmp is a non-local goto.
• ✅ Non-local goto are generated by both setjmp and longjmp.
• ✅ Longjmp is a local goto, and setjmp sets a local jump.

Explanation:

Option A is the correct answer. Setjmp saves the current state so that longjmp can use it later, which is a non-local goto in the protected environment.

1. Regarding structural padding in C, which of the following is true?

• ✅ Structural padding is used to conserve memory.
• ✅ Structure padding guarantees that parts of the structure fit well in memory.
• ✅ Only the array is affected by structural padding.
• ✅ Structural padding is used to ensure that structures are the same size.

Explanation:

Option b is the correct answer. Structural padding is used to ensure that the members of a structure align according to the alignment specifications of the platform.

1. Which of the following actions in C are negated?

• ✅ Adding a pointer with an integer.
• ✅ Deducting a number from a reference.
• ✅ Analyzing two arrows.
• ✅ Incrementing an integer with a pointer.

Explanation:

Option d is the correct answer. You can't increment an integer with a pointer. Multiplication doesn't work properly on pointers, but you can add, subtract, and compare integers.

1. What does it mean when the extend keyword is used for variable declaration in C programming?

• ✅ It means that the variable is defined globally in another file.
• ✅ The variable is a globally accessible local variable.
• ✅ Variables are allocated dynamically at runtime.
• ✅ For quick access, the variable is kept in a register

Explanation:

Option A is the accurate choice. The extern keyword is employed to signify a global variable that has been declared in a different file, enabling multiple files to utilize the same variable.

The outcome of the sizeof(char) expression in C varies based on the system in use.

Explanation:

Option b is the correct answer. The C standard states that a character can be only 1 byte, independent of the order.

1. Which of the following option represent a segmentation failure in C?

• ✅ Error resulting from a division of zero.
• ✅ An error caused by a syntax error in the program.
• ✅ Error resulting from an infinite loop.
• ✅ An error is raised when a program tries to access the memory which is not authorized.

Explanation:

Option d is the correct answer. Segmentation error occurs when a program tries to access memory for which it does not have access; it is usually occurs due to an invalid pointer specified.

1. Which of the following refers to the use of assert.h in C?

• ✅ It provides ways to allocate memory dynamically.
• ✅ Provides a means to terminate the program if a condition is not met.
• ✅ It has functions to perform calculations in mathematics.
• ✅ Provides features for managing file input/output systems.

Explanation:

Option b is the correct answer. Typically, the macro asserts in assert.h is used for debugging. If any condition fails in the c program, assert.h can be used to terminate the program.

1. What is the main function of C's inline keyword?

• ✅ To recommend that the function be optimized by the compiler to run more quickly.
• ✅ To recommend that the function be expanded inline at the place of call by the compiler.
• ✅ To enable access to the function from other translation units.
• ✅ To make the function's implementation in assembly language mandatory.

Explanation:

Option b is the correct answer. The inline keyword tells the compiler to extend the inline function instead of calling the standard function.

1. What is the use of C #define directive?

• ✅ Macros are defined for functions or constants.
• ✅ Includes program standard libraries.
• ✅ The memory is allocated dynamically.
• ✅ If a condition becomes false, it closes the program.

Explanation:

Option A is the accurate choice. Developers have the ability to employ meaningful titles for constants or functions instead of fixed values through the generation of macro definitions for them utilizing the #define command.