CODEWITHSUNDEEP
c#.netc#-4.0
Milind Anantwar
Milind Anantwar

Reputation: 82241

Default parameter vs No Parameter

I have two methods as shown below. One with no parameters and one with only optional parameters.

void GetNext(){
   //implimentation
}

void GetNext(int currentindex = 0){
   //implimentation
}

Now which method will be invoked when a call is given to GetNext with no argument 

 GetNext();

and why?

FYI : This has been asked in one of the interview.

Upvotes: 1

Views: 93

Answers (3)

Mostafiz
Mostafiz

Reputation: 7352

Without parameter method GetNext() will be called

void GetNext(){
   //implimentation
}

because the preference is to call the without parameter method rather than the optional parameter overloaded method

The Overload Resolution

  • A method, indexer, or constructor is a candidate for execution if each of its parameters either is optional or corresponds, by name or by position, to a single argument in the calling statement, and that argument can be converted to the type of the parameter.

  • If more than one candidate is found, overload resolution rules for preferred conversions are applied to the arguments that are explicitly specified. Omitted arguments for optional parameters are ignored.

  • If two candidates are judged to be equally good, preference goes to a candidate that does not have optional parameters for which arguments were omitted in the call. This is a consequence of a general preference in overload resolution for candidates that have fewer parameters.

Upvotes: 0

krivtom
krivtom

Reputation: 24916

Method without optional parameter (GetNext()) is called. Answer why can be found in MSDN:

If two candidates are judged to be equally good, preference goes to a candidate that does not have optional parameters for which arguments were omitted in the call. This is a consequence of a general preference in overload resolution for candidates that have fewer parameters.

Upvotes: 2

Rom
Rom

Reputation: 1193

void GetNext() will be called, in this case the method with the optional parameter is hidden. But if you call GetNext(1), GetNext(int currentindex = 0) will be called.

Upvotes: 0

Related Questions