C Programming Language Mcq Exercise 3

• ✅ register
• ✅ static
• ✅ constant

Explanation:

The correct answer is d. In C, auto, register, and static are storage class specifiers; constant is not. The correct term is const, which is a type qualifier.

1. Which of the following is the correct initialization of a 2d array with 2 digits and 3 digits?

• ✅ int arr[2, 3];
• ✅ int arr2={{1,2,3},{4,5,6}};
• ✅ int arr={1,2,3,4,5,6};
• ✅ int arr2={1,2,3,4,5,6};

Explanation:

The correct answer is b. The proper approach to initialize a 2D array is to specify its dimensions and provide the values for each row in curly brackets.

1. Which of the following claims regarding C's recursion is accurate?

• ✅ The base case is a requirement for all recursive functions.
• ✅ Iterating is never more efficient than recursion.
• ✅ Only integer functions can be utilized with recursion.
• ✅ In C, recursion is disallowed.

Explanation:

The right choice is option a. Without a base case to stop a recursive function, there is a possibility of indefinite iteration and stack overflow.

1. What is the outcome of the expression printf("%d", sizeof('A'));?

• ✅ It varies based on the platform.

Explanation:

The correct answer is a. The sizeof the operator in C returns the size of a char, typically 1 byte, when applied to characters such as 'A'. Character literals are usually of type int, but it evaluates to char instead of sizeof('A').

1. What header files are needed to use the C malloc function?

• ✅ stdlib.h
• ✅ stdio.h
• ✅ string.h
• ✅ math.h

Explanation:

The correct answer is a. The stdlib.h header file is needed for dynamic memory allocations using the malloc function.

1. Which of the following options best describes the function of the #define preprocessor command in C?

• ✅ A function is defined.
• ✅ A macro is defined.
• ✅ A header file is included.
• ✅ A variable is initialized.

Explanation:

The correct answer is b. The macro is a piece of code that is preprocessor-replaced before the compilation has been done and it is defined with the #define directive.

1. Which operator in C has the most priority among the following?

• ✅ (multiplication)
• ✅ + (addition)
• ✅ && (logical AND)
• ✅ == (equality)

Explanation:

The correct answer is a. In C, the multiplication operator * takes precedence over the sum operator +, the logical AND && operator, and the parity == operator. Operations in a term are determined by precedence.

1. Which is the right way to declare a function that returns a pointer to a character and accepts an integer pointer as an argument in C?

• ✅ char *func(int ptr);
• ✅ char func(int *ptr);
• ✅ char func(int ptr);
• ✅ char (func)(int );

Explanation:

The correct answer is b. The char func(intptr); is a valid declaration of a function that accepts an integer pointer and returns a character pointer.

1. Which of the following describes the primary function of the typedef keyword in C?

• ✅ To define an additional variable
• ✅ To define a new data type
• ✅ To create an alias for an existing datatype.
• ✅ To define other functions.

Explanation:

The correct answer is c. We can create a new name(alias) for an already existing data type using the typedef keyword in C.

1. Which of the following best summarizes the extern keyword in C?

• ✅ A local variable is defined.
• ✅ A variable is declared but not defined.
• ✅ A change has been initiated.
• ✅ Memory is allocated for the variable.

Explanation:

The correct answer is b. In order to grant access to variables in a particular file, the extern keyword in C is used to declare a variable defined in a different source file or scope

1. What does C's #pragma directive aim to achieve?

• ✅ To include all available libraries.
• ✅ To provide the compiler with extra instructions.
• ✅ To define macros.
• ✅ To declare transactions.

Explanation:

The right choice is option b. Within the C programming language, the #pragma directive plays a crucial role in offering additional details to the compiler, typically concerning the management of the source code, like specifying warning operations or optimization strategies. When the logical expression ! (1 && 0) is employed, it results in a syntax error.

Explanation:

The correct answer is b. Because logical AND (&&) requires both operands to be true, Equation 1 && 0 evaluates to 0. For 0 to be logically NOT(!) is 1.

1. Which of the below C functions reads a single character from the console?

• ✅ scanf
• ✅ printf
• ✅ getchar
• ✅ putchar

Explanation: