Which of the following statements are correct about datatypes in C#.NET?

1. Every datatype is either a value type or a reference type.
2. Value types are always created on the heap.
3. Reference types are always created on the stack.
4. Mapping of every value type to a type in Common Type System facilitates Interoperability in C#.NET.
5. Every reference type gets mapped to a type in Common Type System.

byte a = 11, b = 22, c;

1. Each value type has an implicit default constructor that initializes the default value of that type.
2. It is possible for a value type to contain the null value.
3. All value types are derived implicitly from System.ValueType class.
4. It is not essential that local variables in C# must be initialized before being used.
5. Variables of reference types referred to as objects and store references to the actual data.

int i, j = 1, k;
for (i = 0; i < 5; i++)
{
    k = j++ + ++j;
    Console.Write(k + " ");
}

int a = 10, b = 20, c = 30; 
int res = a < b? a < c? c : a : b; 
Console.WriteLine(res);

1. The conditional operator (?:) returns one of two values depending on the value of a Boolean expression.
2. The as operator in C#.NET is used to perform conversions between compatible reference types.
3. The &* operator is also used to declare pointer types and to dereference pointers.
4. The -> operator combines pointer dereferencing and member access.
5. In addition to being used to specify the order of operations in an expression, brackets [ ] are used to specify casts or type conversions.

Console.WriteLine(13 / 2 + " " + 13 % 2);