C Programming — MCQ Practice Questions & Answers

Question 1

What is the correct way to declare a 1D array of 10 integers in C?

Accepted Answer

Correct answer: A. int arr[10]; — In C, arrays are declared with the syntax: datatype arrayname[size]. Option A follows the correct syntax.

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B. int arr(10);

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C. int arr{10};

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D. int [10]arr;

Question 2

What will be the output of strlen("Hello") in C?

Accepted Answer

Correct answer: B. 5 — strlen() returns the length of the string excluding the null terminator '\0'. "Hello" has 5 characters.

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A. 4

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C. 6

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D. Error

Question 3

Which of the following is NOT a valid string initialization?

Accepted Answer

Correct answer: C. char str[10]; str = "Program"; — Array names are constant pointers and cannot be reassigned. Direct assignment to char array after declaration is invalid.

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A. char str[] = "Program";

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B. char str[10] = {'P','r','o','g'};

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D. char *str = "Program";

Question 4

What does the following code do? strcpy(dest, src);

Accepted Answer

Correct answer: B. Copies string src to dest — strcpy() copies the contents of the source string to the destination string.

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A. Compares two strings

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C. Concatenates two strings

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D. Finds length of string

Question 5

Consider a 2D array declared as: int matrix[3][4]. How many elements does it have?

Accepted Answer

Correct answer: D. 12 — A 2D array with dimensions 3x4 has 3*4 = 12 total elements.

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A. 3

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B. 4

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C. 7

Question 6

If an integer array arr[10] is declared globally in C, what will be the initial values of its elements?

Accepted Answer

Correct answer: A. All elements initialized to 0 — Global arrays in C are automatically initialized to 0 by default. Only local arrays contain garbage values.

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B. All elements contain garbage values

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C. All elements initialized to 1

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D. Elements are uninitialized until explicitly set

Question 7

In C, a string is internally represented as:

Accepted Answer

Correct answer: A. An array of characters terminated by '\0' — In C, strings are null-terminated character arrays. The null character '\0' marks the end of the string.

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B. An array of integers with length prefix

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C. A special data type with built-in length

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D. A pointer to the first character with separate length variable

Question 8

How much memory is allocated for char name[50] declaration?

Accepted Answer

Correct answer: A. 50 bytes — char name[50] allocates exactly 50 bytes. The null terminator '\0' must fit within this 50-byte allocation.

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B. 49 bytes

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C. 51 bytes

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D. Depends on compiler

C Programming - MCQ Practice Questions