Consider the following C function definition. int fX(char *a) char *b = a; while(*b) b++; return b - a; Which of the following statements is/are TRUE? A) The function call fX("abcd") will always return a value B) Assuming a character array c is declared as char c[] = "abcd" in main() , the function call fX(c) will always return a value C) The code of the function will not compile D) Assuming a character pointer c is declared as char *c = "abcd" in main() , the function call fX(c) will always return a value

Official answer: A) The function call fX("abcd") will always return a value; B) Assuming a character array c is declared as char c[] = "abcd" in main() , the function call fX(c) will always return a value; D) Assuming a character pointer c is declared as char *c = "abcd" in main() , the function call fX(c) will always return a value. Explanation: The given function `fX` calculates the length of a null-terminated string (similar to `strlen`): 1. It initializes a pointer `b` to the start of the string `a`. 2. The loop `while(*b)` traverses the characters until it encounters the null-terminating character `\0` (which evaluates to 0 / false). 3. It returns the pointer difference `b - a`, which gives the integer length of the string. Evaluating the statements: - Option A: Passing a string literal `"abcd"` provides a pointer to a valid null-terminated character sequence (`'a'`, `'b'`, `'c'`, `'d'`, `'\0'`). The function terminates and returns 4. Hence, A is TRUE. - Option B: An array declared as `char c[] = "abcd"` is null-terminated and decays to `char *` when passed to `fX(c)`, returning 4. Hence, B is TRUE. - Option C: The syntax of the function is completely valid C code and will compile without errors. Hence, C is FALSE. - Option D: A pointer initialized as `char *c = "abcd"` points to a valid null-terminated string literal, and passing it to `fX(c)` returns 4. Hence, D is TRUE. Thus, statements A, B, and D are TRUE.

A) The function call fX("abcd") will always return a value

B) Assuming a character array c is declared as char c[] = "abcd" in main() , the function call fX(c) will always return a value

C) The code of the function will not compile

D) Assuming a character pointer c is declared as char *c = "abcd" in main() , the function call fX(c) will always return a value

Programming and Data Structures · Programming in C

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GATE CSE 2024 Set 2 Q33 · MSQ · 1 mark

Consider the following C function definition. `int fX(char a) { char b = a; while(*b) b++; return b - a; }` Which of the following statements is/are TRUE?

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Programming in C

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In GATE CS, Programming in C is tested extensively through rigorous code tracing, pointer mechanics, and fundamental semantics rather than high-level syntax trivia. Questions emphasize pointer arithmetic and multidimensional array decay, storage classes (especially static local variables), evaluation order, side effects of increment/decrement operators, parameter passing mechanisms (pass-by-value vs pass-by-reference), and recursive program state tracking. The topic features a nearly balanced split between NAT and MCQ items across 1-mark and 2-mark categories, demanding precise, bug-free execution traces without a compiler.

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Programming and Data Structures · Programming in C

Official IIT answer key · IISc Bangalore · Audited Aug 2026

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GATE CSE 2024 Set 2 Q33 · MSQ · 1 mark

Consider the following C function definition. `int fX(char a) { char b = a; while(*b) b++; return b - a; }` Which of the following statements is/are TRUE?

Select one or more options

Key concept

Programming in C

Step-by-step verified solution

Examiner trap & misconception

Topic notes

How GATE tests Programming in C

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Independent practice explanation verified by the GateAI team. GATE is conducted by the IITs; question text follows the official paper.

Consider the following C function definition. `int fX(char a) { char b = a; while(*b) b++; return b - a; }` Which of the following statements is/are TRUE?

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Consider the following C function definition. `int fX(char a) { char b = a; while(*b) b++; return b - a; }` Which of the following statements is/are TRUE?

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Consider the following C function definition. int fX(char *a) { char *b = a; while(*b) b++; return b - a; } Which of the following statements is/are TRUE?

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Consider the following C function definition. int fX(char *a) { char *b = a; while(*b) b++; return b - a; } Which of the following statements is/are TRUE?

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Consider the following C function definition. `int fX(char a) { char b = a; while(*b) b++; return b - a; }` Which of the following statements is/are TRUE?

Consider the following C function definition. `int fX(char a) { char b = a; while(*b) b++; return b - a; }` Which of the following statements is/are TRUE?