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Nov 28, 2012 · In Java 8, methods can be created as Lambda expressions and can be passed by reference (with a little work under the hood). There are plenty of examples online with lambdas being created and used with methods, but no examples of how to make a method taking a lambda as a parameter.
I want to sort String elements in the array months by length using Arrays.sort method. I was told here, that it's possible to use lambda expressions instead of creating new class implementing Compa...
Feb 14, 2015 · Now note, casting to a lambda is different from ((Foo & Bar) o).bar();. In case of lambda, you are initializing the lambda with its type as the declared target type. But with ((Foo & Bar) o).bar();, you are type-casting the variable o to be of Foo and Bar. In former case, you are setting the type.
The idea of lambda expressions is that instead of creating a class that implements a functional interface, you can define a lambda expression of the type of that interface. For example, your Merge class implements BinaryOperator<int[]> and can be replaced by the following lambda expression :
Feb 24, 2015 · I have been using Java 8 for some months, and I have started to use Lambda expressions, which are very convenient for some cases. However, I often come across some problems to unit test the code that uses a Lambda. Take as an example the following pseudo-code: private Bar bar; public void method(int foo){ bar.useLambda(baz -> baz.setFoo(foo)); }
Nov 26, 2016 · These aren't different "kinds" of lambda expressions (and you've not even exhaustively covered the options). The third is merely a special case of the first, where there are simply zero arguments. The second is a special syntactic form, where you can omit the parentheses if there is exactly one argument and you've chosen to let the compiler infer the argument types.
A Java ActionListener must implement just one single method (actionPerformed(ActionEvent e)). This fits nicely into the Java 8 function so Java 8 provides a simple lambda to implement an ActionListener. The MouseAdapter requires at least two methods so does not fit as a function.
Oct 3, 2015 · lambda expressions are not supported in -source 1.7 4 strings in switch are not supported in -source 1.5 [ERROR] (use -source 7 or higher to enable strings in switch)
Just set a breakpoint and be sure not to inspect the whole lambda expression (inspect only the lambda body). Another approach is to use peek to inspect the elements of the stream: List<Integer> naturals = Arrays.asList(1,2,3,4,5,6,7,8,9,10,11,12,13); naturals.stream() .map(n -> n * 2) .peek(System.out::println) .collect(Collectors.toList());
Jul 22, 2016 · The equivalent foreach loop in Java is structured like this. List<Foo> fooList = // some list containing foos for (Foo foo : fooList){ // do stuff } There are no lambda expressions in Java, however if you can wait until Java8 they are adding closures. The closest you can get are anonymous inner classes.
