Let’s look at an example: def f(value, key, hash={}): hash[value] = key return hash print(f(‘a’, 1)) print(f(‘b’, 2)) Which you probably expect to output: {‘a’: 1} {‘b’: 2} But actually outputs: {‘a’: 1} {‘a’: 1, ‘b’: 2}
You can simply use: mvn –settings YourOwnSettings.xml clean install or mvn -s YourOwnSettings.xml clean install
No. A workaround is to overload with another method that doesn’t have out / ref parameters, and which just calls your current method. public bool SomeMethod(out string input) { … } // new overload public bool SomeMethod() { string temp; return SomeMethod(out temp); } If you have C# 7.0, you can simplify: // new overload … Read more
What is the double pipe operator (||)? The double pipe operator (||) is the logical OR operator . In most languages it works the following way: If the first value is false, it checks the second value. If that’s true, it returns true and if the second value is false, it returns false. If the … Read more
There are two related concepts, both called “keyword arguments“. On the calling side, which is what other commenters have mentioned, you have the ability to specify some function arguments by name. You have to mention them after all of the arguments without names (positional arguments), and there must be default values for any parameters which … Read more
ES2015 and later In ES2015, parameter destructuring can be used to simulate named parameters. It would require the caller to pass an object, but you can avoid all of the checks inside the function if you also use default parameters: myFunction({ param1 : 70, param2 : 175}); function myFunction({param1, param2}={}){ // …function body… } // … Read more
Just use the *args parameter, which allows you to pass as many arguments as you want after your a,b,c. You would have to add some logic to map args->c,d,e,f but its a “way” of overloading. def myfunc(a,b, *args, **kwargs): for ar in args: print ar myfunc(a,b,c,d,e,f) And it will print values of c,d,e,f Similarly you … Read more
UPDATE: This question was the subject of my blog on May 12th 2011. Thanks for the great question! Suppose you have an interface as you describe, and a hundred classes that implement it. Then you decide to make one of the parameters of one of the interface’s methods optional. Are you suggesting that the right … Read more
1. Using default implementations (preferred). protocol MyProtocol { func doSomething() } extension MyProtocol { func doSomething() { /* return a default value or just leave empty */ } } struct MyStruct: MyProtocol { /* no compile error */ } Advantages No Objective-C runtime is involved (well, no explicitly at least). This means you can conform … Read more
Surprised no one mentioned C# 4.0 optional parameters that work like this: public void SomeMethod(int a, int b = 0) { //some code } Edit: I know that at the time the question was asked, C# 4.0 didn’t exist. But this question still ranks #1 in Google for “C# optional arguments” so I thought – … Read more