Why is this an issue?
Generally, writing the least code that will readably do the job is a good thing, so omitting default parameter values seems to make sense.
Unfortunately, when you omit them from the base call in an override, you’re not actually getting the job done thoroughly, because you’re
ignoring the value the caller passed in. The result will likely not be what the caller expected.
Noncompliant code example
public class BaseClass
{
public virtual void MyMethod(int i = 1)
{
Console.WriteLine(i);
}
}
public class DerivedClass : BaseClass
{
public override void MyMethod(int i = 1)
{
// ...
base.MyMethod(); // Noncompliant; caller's value is ignored
}
static int Main(string[] args)
{
DerivedClass dc = new DerivedClass();
dc.MyMethod(12); // prints 1
}
}
Compliant solution
public class BaseClass
{
public virtual void MyMethod(int i = 1)
{
Console.WriteLine(i);
}
}
public class DerivedClass : BaseClass
{
public override void MyMethod(int i = 1)
{
// ...
base.MyMethod(i);
}
static int Main(string[] args)
{
DerivedClass dc = new DerivedClass();
dc.MyMethod(12); // prints 12
}
}
