C# – Will GetType() return the most derived type when called from the base class

cinheritancepolymorphism

Will GetType() return the most derived type when called from the base class?

Example:

public abstract class A
{
    private Type GetInfo()
    {
         return System.Attribute.GetCustomAttributes(this.GetType());
    }
}

public class B : A
{
   //Fields here have some custom attributes added to them
}

Or should I just make an abstract method that the derived classes will have to implement like the following?

public abstract class A
{
    protected abstract Type GetSubType();

    private Type GetInfo()
    {
         return System.Attribute.GetCustomAttributes(GetSubType());
    }
}

public class B : A
{
   //Fields here have some custom attributes added to them

   protected Type GetSubType()
   {
       return GetType();
   }
}

Best Answer

GetType() will return the actual, instantiated type. In your case, if you call GetType() on an instance of B, it will return typeof(B), even if the variable in question is declared as a reference to an A.

There is no reason for your GetSubType() method.

Related Solutions

C++ – How to call a parent class function from derived class function

I'll take the risk of stating the obvious: You call the function, if it's defined in the base class it's automatically available in the derived class (unless it's private).

If there is a function with the same signature in the derived class you can disambiguate it by adding the base class's name followed by two colons base_class::foo(...). You should note that unlike Java and C#, C++ does not have a keyword for "the base class" (super or base) since C++ supports multiple inheritance which may lead to ambiguity.

class left {
public:
    void foo();
};

class right {
public:
    void foo();
};

class bottom : public left, public right {
public:
    void foo()
    {
        //base::foo();// ambiguous
        left::foo();
        right::foo();

        // and when foo() is not called for 'this':
        bottom b;
        b.left::foo();  // calls b.foo() from 'left'
        b.right::foo();  // call b.foo() from 'right'
    }
};

Incidentally, you can't derive directly from the same class twice since there will be no way to refer to one of the base classes over the other.

class bottom : public left, public left { // Illegal
};

C# – Case insensitive ‘Contains(string)’

You could use the String.IndexOf Method and pass StringComparison.OrdinalIgnoreCase as the type of search to use:

string title = "STRING";
bool contains = title.IndexOf("string", StringComparison.OrdinalIgnoreCase) >= 0;

Even better is defining a new extension method for string:

public static class StringExtensions
{
    public static bool Contains(this string source, string toCheck, StringComparison comp)
    {
        return source?.IndexOf(toCheck, comp) >= 0;
    }
}

Note, that null propagation ?. is available since C# 6.0 (VS 2015), for older versions use

if (source == null) return false;
return source.IndexOf(toCheck, comp) >= 0;

USAGE:

string title = "STRING";
bool contains = title.Contains("string", StringComparison.OrdinalIgnoreCase);

Best Answer

Related Solutions

C++ – How to call a parent class function from derived class function

C# – Case insensitive ‘Contains(string)’

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