The return there is returning from the lambda expression rather than from the containing method. Instead of forEach you need to filter the stream: players.stream().filter(player -> player.getName().contains(name)) .findFirst().orElse(null); Here filter restricts the stream to those items that match the predicate, and findFirst then returns an Optional with the first matching entry. This looks less efficient … Read more
SLaks and Killercam’s answers are good; I thought I’d just add a bit more context. Your first question is essentially about what methods can be marked async. A method marked as async can return void, Task or Task<T>. What are the differences between them? A Task<T> returning async method can be awaited, and when the … Read more
This question was the subject of my blog on June 23rd 2011. Thanks for the great question! The C# team is considering this for C# 7. See https://github.com/dotnet/roslyn/issues/5233 for details. UPDATE: The feature made it in to C# 7! You are correct; .NET does support methods that return managed references to variables. .NET also supports … Read more
Use RETURN QUERY: CREATE OR REPLACE FUNCTION word_frequency(_max_tokens int) RETURNS TABLE (txt text — also visible as OUT param in function body , cnt bigint , ratio bigint) LANGUAGE plpgsql AS $func$ BEGIN RETURN QUERY SELECT t.txt , count(*) AS cnt — column alias only visible in this query , (count(*) * 100) / _max_tokens … Read more
This seems to be answered – #include <fstream>. The message means :- incomplete type – the class has not been defined with a full class. The compiler has seen statements such as class ifstream; which allow it to understand that a class exists, but does not know how much memory the class takes up. The … Read more
PHP 7.1 Now supports nullable return types. The first RFC I linked to is the one they went for: function nullOrString(int $foo) : ?string { return $foo%2 ? “odd” : null; } old answer: Since my comment was actually an answer to the question: PHP 7 won’t support nullable return-types just yet, but there’s an … Read more
You need to make it a generic method, like this: public static T ConfigSetting<T>(string settingName) { return /* code to convert the setting to T… */ } But the caller will have to specify the type they expect. You could then potentially use Convert.ChangeType, assuming that all the relevant types are supported: public static T … Read more
I usually do this using zip: >>> df = pd.DataFrame([[i] for i in range(10)], columns=[‘num’]) >>> df num 0 0 1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 >>> def powers(x): >>> return x, x**2, x**3, x**4, x**5, x**6 >>> df[‘p1’], df[‘p2’], df[‘p3’], df[‘p4’], df[‘p5’], … Read more
From the documentation class typing.Union Union type; Union[X, Y] means either X or Y. Hence the proper way to represent more than one return data type is from typing import Union def foo(client_id: str) -> Union[list,bool] But do note that typing is not enforced. Python continues to remain a dynamically-typed language. The annotation syntax has … Read more
The return value for main indicates how the program exited. Normal exit is represented by a 0 return value from main. Abnormal exit is signaled by a non-zero return, but there is no standard for how non-zero codes are interpreted. As noted by others, void main() is prohibited by the C++ standard and should not … Read more