Mastering Pointers in C++

What is a pointer in C++?

• A pointer is a type of function in C++.

• A pointer is a variable that stores a string in C++.

• A pointer is a special kind of loop in C++.

• A pointer is a variable that holds the address of another variable in C++.

How do you declare a pointer variable?

• int ptr;

• pointer int ptr;

• *int ptr;

• int *ptr;

What is the purpose of the 'new' operator in memory management?

• To allocate memory for a new object and initialize it.

• To create a copy of an existing object.

• To free up memory used by an object.

• To check if an object is null.

Explain the difference between a pointer and a reference.

• A pointer is always initialized, while a reference can be uninitialized.

• A pointer can only point to integers, while a reference can point to any data type.

• A pointer is a type of variable, while a reference is a function.

• A pointer holds a memory address and can be reassigned; a reference is an alias for a variable and cannot be changed.

What happens if you dereference a null pointer?

• Dereferencing a null pointer results in a warning but continues execution.

• Dereferencing a null pointer returns a valid memory address.

• Dereferencing a null pointer results in undefined behavior, often causing a program crash.

• Dereferencing a null pointer automatically fixes the error.

How can you dynamically allocate an array using pointers?

• Use 'int array[n];' to declare a static array.

• Use 'array = malloc(n);' without specifying size of int.

• Use 'int *array = (int *)malloc(n * sizeof(int));' to allocate an array of 'n' integers.

• Allocate memory using 'new int[n];' in C.

What is a memory leak and how can it occur in C++?

• A memory leak in C++ is when allocated memory is not released, often due to lost pointers after using 'new' without corresponding 'delete'.

• A memory leak is when memory is allocated but immediately freed.

• Memory leaks happen when using 'delete' without 'new'.

• A memory leak occurs when memory is automatically released after use.

How do you free dynamically allocated memory?

• Use 'free(pointer)' for malloc/calloc/realloc and 'delete pointer' for new.

• Invoke 'clear(pointer)' to release memory

• Call 'remove(pointer)' for new allocations

• Use 'dispose(pointer)' for malloc/calloc/realloc

What is the role of the 'delete' operator?

• The 'delete' operator creates a new object without any properties.

• The 'delete' operator removes a property from an object.

• The 'delete' operator modifies the value of a property in an object.

• The 'delete' operator adds a property to an object.

Explain the concept of pointer arithmetic.

• Pointer arithmetic is only applicable to integer data types.

• Pointer arithmetic allows you to navigate through memory addresses based on the data type size, enabling efficient array and data structure manipulation.

• Pointer arithmetic is a method for sorting arrays in descending order.

• Pointer arithmetic is used to allocate memory dynamically without any data type consideration.