Which of the following does not initialize ptr to null (assuming variable…

2026

Which of the following does not initialize ptr to null (assuming variable declaration of a as int a=0)?

Answer: A. int*ptr=&a;To determine which option does not initialize ptr to null, analyze each option: Option A: int*ptr=&a; assigns the address of a to ptr. Since a is a valid…

  1. A.

    int*ptr=&a;

  2. B.

    int *ptr = &a- &a;

  3. C.

    int *ptr=a-a;

  4. D.

    none of these

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Correct answer: A

To determine which option does not initialize ptr to null, analyze each option:

Option A: int*ptr=&a; assigns the address of a to ptr. Since a is a valid variable, ptr points to a memory location and is not null.

Option B: int *ptr = &a - &a; subtracts the address of a from itself, resulting in 0. Assigning 0 to a pointer initializes it to null.

Option C: int *ptr = a - a; subtracts a from itself, resulting in 0. Assigning 0 to a pointer initializes it to null.

Option D: 'none of these' implies that all options initialize ptr to null. However, Option A does not, so this option is incorrect.

Therefore, the option that does not initialize ptr to null is Option A.

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