Tutorial by Examples: f

// Java: Map<Boolean, List<Student>> passingFailing = students.stream() .collect(Collectors.partitioningBy(s -> s.getGrade() >= PASS_THRESHOLD)); // Kotlin: val passingFailing = students.partition { it.grade >= PASS_THRESHOLD }

// Java: List<String> namesOfMaleMembersCollect = roster .stream() .filter(p -> p.getGender() == Person.Sex.MALE) .map(p -> p.getName()) .collect(Collectors.toList()); // Kotlin: val namesOfMaleMembers = roster.filter { it.gender == Person.Sex.MALE }.map { it.nam...

// Java: Map<Person.Sex, List<String>> namesByGender = roster.stream().collect( Collectors.groupingBy( Person::getGender, Collectors.mapping( Person::getName, Collectors.toList()))); // ...

// Java: List<String> filtered = items.stream() .filter( item -> item.startsWith("o") ) .collect(Collectors.toList()); // Kotlin: val filtered = items.filter { item.startsWith('o') }

// Java: String shortest = items.stream() .min(Comparator.comparing(item -> item.length())) .get(); // Kotlin: val shortest = items.minBy { it.length }

// Java: Stream.of("a1", "a2", "a3") .findFirst() .ifPresent(System.out::println); // Kotlin: sequenceOf("a1", "a2", "a3").firstOrNull()?.apply(::println)

// Java: IntStream.range(1, 4).forEach(System.out::println); // Kotlin: (inclusive range) (1..3).forEach(::println)

// Java: Arrays.stream(new int[] {1, 2, 3}) .map(n -> 2 * n + 1) .average() .ifPresent(System.out::println); // 5.0 // Kotlin: arrayOf(1,2,3).map { 2 * it + 1}.average().apply(::println)

// Java: Stream.of("a1", "a2", "a3") .map(s -> s.substring(1)) .mapToInt(Integer::parseInt) .max() .ifPresent(System.out::println); // 3 // Kotlin: sequenceOf("a1", "a2", "a3") .map { it.substring(1) } ...

// Java: IntStream.range(1, 4) .mapToObj(i -> "a" + i) .forEach(System.out::println); // a1 // a2 // a3 // Kotlin: (inclusive range) (1..3).map { "a$it" }.forEach(::println)

// Java: Stream.of(1.0, 2.0, 3.0) .mapToInt(Double::intValue) .mapToObj(i -> "a" + i) .forEach(System.out::println); // a1 // a2 // a3 // Kotlin: sequenceOf(1.0, 2.0, 3.0).map(Double::toInt).map { "a$it" }.forEach(::println)

// Java: long count = items.stream().filter( item -> item.startsWith("t")).count(); // Kotlin: val count = items.filter { it.startsWith('t') }.size // but better to not filter, but count with a predicate val count = items.count { it.startsWith('t') }

// Java: List<String> myList = Arrays.asList("a1", "a2", "b1", "c2", "c1"); myList.stream() .filter(s -> s.startsWith("c")) .map(String::toUpperCase) .sorted() .forEach(System.out::println); // C1 ...

// Java: Arrays.asList("a1", "a2", "a3") .stream() .findFirst() .ifPresent(System.out::println); // Kotlin: listOf("a1", "a2", "a3").firstOrNull()?.apply(::println) or, create an extension function on String calle...

// Java: String phrase = persons .stream() .filter(p -> p.age >= 18) .map(p -> p.name) .collect(Collectors.joining(" and ", "In Germany ", " are of legal age.")); System.out.println(phrase); // In Germany Max and Peter a...

<link rel="icon" type="image/png" href="/favicon.png"> <link rel="shortcut icon" type="image/x-icon" href="/favicon.ico"> Use the mime-type image/png for PNG files and image/x-icon for icon (*.ico) files. For the difference...

Once you have a Dockerfile, you can build an image from it using docker build. The basic form of this command is: docker build -t image-name path If your Dockerfile isn't named Dockerfile, you can use the -f flag to give the name of the Dockerfile to build. docker build -t image-name -f Dockerfi...

FROM node:5 The FROM directive specifies an image to start from. Any valid image reference may be used. WORKDIR /usr/src/app The WORKDIR directive sets the current working directory inside the container, equivalent to running cd inside the container. (Note: RUN cd will not change the current ...

Have you ever forgotten to add a trap to clean up a temporary file or do other work at exit? Have you ever set one trap which canceled another? This code makes it easy to add things to be done on exit one item at a time, rather than having one large trap statement somewhere in your code, which may...

When using GraphAll you may still want to filter the results, in which case you can use an Alert variable with the Filter, Sort, and Limit functions. template graph.template { subject = ... body = `{{template "header" .}} <strong>Graph Filtered Variable</strong...