Which of the following statements are correct?

1. A switch statement can act on numerical as well as Boolean types.
2. A switch statement can act on characters, strings and enumerations types.
3. We cannot declare variables within a case statement if it is not enclosed by { }.
4. The foreach statement is used to iterate through the collection to get the desired information and should be used to change the contents of the collection to avoid unpredictable side effects.
5. All of the expressions of the for statement are not optional.

class Sample
{
    public int func(int i, Single j)
    {
        /* Add code here. */
    }
}

1. A struct can contain properties.
2. A struct can contain constructors.
3. A struct can contain protected data members.
4. A struct cannot contain methods.
5. A struct cannot contain constants.

1. An attribute can be inspected at link-time.
2. An attribute can be inspected at compile-time.
3. An attribute can be inspected at run-time.
4. An attribute can be inspected at design-time.

1. A class
2. A property
3. A struct
4. A function
5. An interface