C++ Programming

Question: Is there any difference int the following declarations?int fun(int arr[]);int fun(int arr[2]);
[A].

Yes

[B].

No

Answer: Option B

Explanation:

No, both the statements are same. It is the prototype for the function fun() that accepts one integer array as an parameter and returns an integer value.

Question: In C, if you pass an array as an argument to a function, what actually gets passed?
[A].

Value of elements in array

[B].

First element of the array

[C].

Base address of the array

[D].

Address of the last element of array

Answer: Option C

Explanation:

The statement ‘C’ is correct. When we pass an array as a funtion argument, the base address of the array will be passed.

Question: A pointer to a block of memory is effectively same as an array
[A].

True

[B].

False

Answer: Option A

Explanation:

Yes, It is possible to allocate a block of memory (of arbitrary size) at run-time, using the standard library’s malloc function, and treat it as an array.

Question: Which of the following statements are correct about the program below?

[A].

The code is erroneous since the subscript for array used in for loop is in the range 1 to size.

[B].

The code is erroneous since the values of array are getting scanned through the loop.

[C].

The code is erroneous since the statement declaring array is invalid.

[D].

The code is correct and runs successfully.

Answer: Option C

Explanation:

The statement int arr[size]; produces an error, because we cannot initialize the size of array dynamically. Constant expression is required here.

Example: int arr[10];

One more point is there, that is, usually declaration is not allowed after calling any function in a current block of code. In the given program the declaration int arr[10]; is placed after a function call scanf().

Question: Are the expressions arr and &arr same for an array of 10 integers?
[A].

Yes

[B].

No

Answer: Option B

Explanation:

Both mean two different things. arr gives the address of the first int, whereas the &arr gives the address of array of ints.

Question: Does this mentioning array name gives the base address in all the contexts?
[A].

Yes

[B].

No

Answer: Option B

Explanation:

No, Mentioning the array name in C or C++ gives the base address in all contexts except one.

Syntactically, the compiler treats the array name as a pointer to the first element. You can reference elements using array syntax, a[n], or using pointer syntax, *(a+n), and you can even mix the usages within an expression.

When you pass an array name as a function argument, you are passing the “value of the pointer”, which means that you are implicitly passing the array by reference, even though all parameters in functions are “call by value”.