C# DataType MCQs

Question 1: Which of the following data types can include maximum positive or negative, integer or float value?

Answer: C

The BigInteger type is an immutable type that represents an arbitrarily large integer whose value, in theory, has no upper or lower bounds. Learn C# BigInteger.

Question 2: Which of the following data type will you use to store the monetary value?

Answer: D

The decimal type is a 128-bit data type suitable for financial and monetary calculations. The decimal type can represent values ranging from 1.0 * 10^-28 to approximately 7.9 * 10^28 with 28-29 significant digits. Visit Decimal types for more information.

Question 3: What will be the output of the following program?

public static void Main()
{
    float x = 30.423f;
    long y = 20L, 
    z = x+y;

    Console.WriteLine(z);
}

Answer: C

In C#, you cannot convert float to long implicitly. You must cast explicitly e.g. z = (long) x+y;

Question 4: Which of the following is a reference type?

Answer: C

String is a reserved word (alias) for System.String class. It is immutable reference type. Learn C# String.

Question 5: Which of the following is a value type?

Answer: A, B, C,

The number types such as int, float is the value type. Struct is also a value type. String and ArrayList are reference types. Learn value types and reference types in C#.

Question 6: What will be the output of the following program?

public static void Main(string[] args)
 {
    float f = 10.5F;
    int i = 20;
    var sum = f + i;

    Console.Write(sum);
}

Answer: B

Here, sum is an implicitly-typed variable whose data type will be determined at compile-time, and so it would be float type.

Question 7: You want to hold the largest positive integer value in a variable. Which of the following data type will you use for a variable?

Answer: C

Ulong. Ulong can store the value from 0 to 18,446,744,073,709,551,615 and occupies 8 bytes in the memory. Learn C# data types.

Question 8: If you want to hold a positive integer value up to 250. Which of the following data type will you use for a variable?

Answer: C

The byte data type can store a value from 0 to 255 and occupies only 1 byte in the memory. Learn C# data types.

Question 9: What will be the output of following code?

Console.WriteLine(Convert.ToInt32('A'));

Answer: C

Conversion of character to integer will return an ASCII value.

Question 10: What will be the output of the following program?:

public static void Main(string[] args)
{
    int x = 5;
    square(x);
    Console.Write(x);
}

static void square(int x)
{
    x = x * x;
}

Answer: A

An int is a value type, and so it will always be passed as by value, not the reference. Hence, the value of x in the Main() would remain the same.