Summary: CLR via C # (Chapter 8): Others (method transfer, out, ref)

Pass parameters to the method by referencing:

1,OutAndRefDifferences:

If the method parameter is markedOut,Parameter can be not initialized, But the object must be assigned a value before the return;

If the method parameter is markedRef, The parameter must be initialized before the call;

That is, keywords are used for a large number of value types.OutAfter,CodeHigher efficiency;

2,CLRAllow method-basedOutAndRefParameters are used to overload methods, but onlyOutAndRefThe difference method is not allowed;

Static VoidAdd (IntI)

{

}

 

Static VoidAdd (Out IntI)

{

}

If you add the following method, an error occurs.

// Error:"Add"It cannot be defined that there are different overload methods on ref and out.

Static VoidAdd (Ref IntI)

{

}

 

To pass a variable number of parameters to the method:

KeywordsParamsIs the last Parameter Applied to the method signature;

Private Static Int32Add (Params Int32[] Values ){

// Note: It is possible to pass the 'values'

// Array to other methods if you want.

 

Int32Sum = 0;

For(Int32X = 0; x <values. length; X ++)

Sum + = values [x];

ReturnSUM;

}

 

Private Static VoidDisplaytypes (Params Object[] Objects ){

Foreach(ObjectOInObjects)

Console. Writeline (O. GetType ());

}

Note: calls to methods that can accept the number of variable parameters may cause some extra performance loss;

The best method is to overload the method;

 

The parameter type of the declaration method:

Specify the weak type whenever possible when declaring the parameter type of the method;

Specify a strong type as much as possible;

To retain more flexibility, you can specify a weak type for the return type;