C# Programming Questions and Answers

31

Which statement is correct about following c#.NET code ?

int[] a= {11, 3, 5, 9, 6};

a

’a’ is a reference to the array created on stack

b

’a’ is a reference to an object created on stack

c

’a’ is a reference to an object of a class that compiler drives from ‘System.Array’ class

d

None of the mentioned

correct answer c

A perfect way of defining single array in C# which is derived automatically from class ‘System.Array’

32

Which statement is correct about following set of code ?
int[, ]a={{5, 4, 3},{9, 2, 6}};

a

’a’ represents 1-D array of 5 integers

b

a.GetUpperBound(0) gives 9

c

’a’ represents rectangular array of 2 columns and 3 arrays

d

a.GetUpperBound(1) gives 2

correct answer c,d

By definition Options (C) and (D)

33

What is the advantage of using 2D jagged array over 2D rectangular array?

a

Easy initialization of elements

b

Allows unlimited elements as well as rows which had ‘0’ or are empty in nature

c

All of the mentioned

d

None of the mentioned

correct answer b

In many applications where 2 dimensional arrays are used,not all rows need to have all the elements i.e they are sparse.Many rows have 0 elements.In such cases it is better to use 2D jagged arrays as they allow unequal number of elements in each row and also allow for empty rows.

34

Which statement is correct among the mentioned statements?
1. The for loop works faster than a while loop
2. for( ; ; )implements an infinite loop

a

Only 1 is correct

b

Only 2 is correct

c

Both 1 and 2 are correct

d

Both 1 and 2 are incorrect

correct answer b

Answer: Option (B)

35

Which of the following is not infinite loop?

a

for( ;’0′; )

b

for( ;’0′; )

c

for( ;’1′; )

d

for( ;’1′; )

correct answer b

Answer: Option (B)

36

Select the output for the following set of code :

staticvoid Main(string[] args)

{

int i =-10;

for(;Convert.ToBoolean(Convert.ToInt32(i));

Console.WriteLine(i++));

Console.ReadLine();

}

a

-9 -8 -7 -6 -5 -4 -3 -2 -1

b

-10 -9 -8 -7 -6 -5 -4 -3 -2

c

-10 -9 -8 -7 -6 -5 -4 -3 -2 -1

d

-8 -7 -6 -5 -4 -3 -2 -1

correct answer c

for first value of i = -10.Condition is executed until i!=0.
Output: -10 -9 -8 -7 -6 -5 -4 -3 -2 -1.

37

Select the output for the following set of code :

staticvoid Main(string[] args)

{

int i, j;

for(i =1, j = i; i <=3&& j >=0; i++, j--)

{

if(i == j)

continue;

else

Console.WriteLine(j);

}

Console.ReadLine();

}

a

i = 0, j = 1;

b

i = 1, j = 0;

c

j = 0;

d

None of the mentioned.

correct answer c

Since for i = 1, j = 1 and 1 <= 3 also 1 >= 0 we had i == j.But after i++ and j–. The initial value of ‘j’ which is ‘0’ as j– preferred other than value of ‘j’ in i = j.
Output: j = 0.

38

Select the output for the following set of code :

{

int i;

Console.WriteLine("Hi");

for(i =1; i <=10; i++)

Program.Main(args);

Console.ReadLine();

}

a

Prints ‘Hi’ for one time

b

Prints ‘Hi’ for infinite times

c

Stack overflow exception Condition generated

d

None of above mentioned

correct answer c

Ocurrence of ‘main()’ condition after for loop.
Output: Hi
Hi
.
.
stack overflow exception.

39

Select the output for the following set of code:

staticvoid Main(string[] args)

{

int i, s =0;

for(i =1; i <=10; s = s + i, i++);

{

Console.WriteLine(s);

}

Console.ReadLine();

}

a

Code report error

b

Code runs in infinite loop condition

c

Code gives output as 0 1 3 6 10 15 21 28 36 45

d

Code give output as 55

correct answer d

Since occurrence of termination symbol(;) at end of for loop.
Output: 55.

40

Select the output for the following set of code :

staticvoid Main(string[] args)

{

float f;

for(f = 0.1f; f <=0.5; f +=1)

Console.WriteLine(++f );

Console.ReadLine();

}

a

1.1

b

0.1

c

0.1 0.2 0.3 0.4 0.5

d

None of the mentioned

correct answer a

f =0.1 and ++f = 0.1+1 = 1.1.So,1.1>0.5,Condition fails and hence loop terminates.
Output : 1.1