akshaya P R
This is classic OOP style of hiding method implementations from the caller. The caller simply passes a variable to the method which then does something with the value of the variable and returns another value or produces a side effect as it is in our case.
class LambdaDemo {
public void printSomething(String something) {
System.out.println(something);
}
public static void main(String[] args) {
LambdaDemo lambdaDemo = new LambdaDemo();
String something = "Learning Lambda";
lambdaDemo.printSomething(something);
}
}
see an equivalent implementation that uses behavior passing other than variable passing. To achieve this, we have to create a functional interface that defines that abstracts the behavior instead of a method. A functional interface is an interface that has only one method:
interface Printer {
void print(String val);
}
class LambdaDemo {
public void printSomething(String something, Printer printer) {
//System.out.println(something);
printer.print(something);
}
public static void main(String[] args) {
LambdaDemo lambdaDemo = new LambdaDemo();
Printer printer = new Printer() {
@Override
public void print(String val) {
System.out.println(val);
}
};
String something = "Learning Lambda";
lambdaDemo.printSomething(something, printer);
}
}
public void print(String toPrint) {
System.out.println(toPrint);
}
lambda expressions
interface Printer {
void print(String val);
}
class LambdaDemo {
public void printSomething(String something, Printer printer) {
//System.out.println(something);
printer.print(something);
}
public static void main(String[] args) {
LambdaDemo lambdaDemo = new LambdaDemo();
Printer printer = (String toPrint) -> {
System.out.println(toPrint);
};
String something = "Learning Lambda";
lambdaDemo.printSomething(something, printer);
}
}
(String toPrint) -> {
System.out.println(toPrint);
}
package com.kg.lambdaapp;
interface Printer {
void print(String something);
}
public class LambdaDemo {
public static void printSomething(String something) {
System.out.println(something);
//printer.print(something);
}
public static void main(String[] args) {
//LambdaDemo lambdaDemo = new LambdaDemo();
String something = "Learning Lambda";
Printer printer = LambdaDemo::printSomething;
printer.print(something);
}
}
package com.kg.lambdaapp;
interface Printer {
void print();
}
public class LambdaDemo {
public static void printSomething() {
System.out.println("something");
//printer.print(something);
}
public static void main(String[] args) {
//LambdaDemo lambdaDemo = new LambdaDemo();
String something = "Learning Lambda";
Printer printer = LambdaDemo::printSomething;
printer.print();
}
}
end
Suriyan S
Stream mapToDouble(ToDoubleFunction<? super T> mapper) returns a DoubleStream consisting of the results of applying the given function to the elements of this stream.
It returns a DoubleStream consisting of the results of replacing each element of this stream with the contents of a mapped stream produced by applying the provided mapping function to each element. Each mapped stream is closed after its contents have placed been into this stream. (If a mapped stream is null an empty stream is used, instead.)
DoubleStream mapToDouble(ToDoubleFunction<? super T> mapper)import java.util.Arrays;
import java.util.List;
public class Main {
public static void main(String[] args) {
List<String> stringList = Arrays.asList("1.2","2.2","3","4","5");
stringList.stream()
.mapToDouble(n-> Double.parseDouble(n) )
.filter(n-> n%2 == 0)
.forEach(System.out::println);
}
}The code above generates the following result.
4.0Stream mapToInt(ToIntFunction<? super T> mapper) returns an IntStream by applying the given function to this stream.
It returns an IntStream consisting of the results of replacing each element of this stream with the contents of a mapped stream produced by applying the provided mapping function to each element. Each mapped stream is closed after its contents have been placed into this stream. (If a mapped stream is null an empty stream is used, instead.)
IntStream mapToInt(ToIntFunction<? super T> mapper)
import java.util.Arrays;
import java.util.List;
public class Main {
public static void main(String[] args) {
List<String> stringList = Arrays.asList("1","2","3","4","5");
stringList.stream()
.mapToInt(n-> Integer.parseInt(n) )
.filter(n-> n%2 == 0)
.forEach(System.out::println);
}
}The code above generates the following result.
2
4Stream mapToLong(ToLongFunction<? super T> mapper) returns a LongStream by applying the function to the stream.
It returns a LongStream consisting of the results of replacing each element of this stream with the contents of a mapped stream produced by applying the provided mapping function to each element. Each mapped stream is closed after its contents have been placed into this stream. (If a mapped stream is null an empty stream is used, instead.)
LongStream mapToLong(ToLongFunction<? super T> mapper)import java.util.Arrays;
import java.util.List;
public class Main {
public static void main(String[] args) {
List<String> stringList = Arrays.asList("1","2","3","4","5");
stringList.stream()
.mapToLong(n-> Long.parseLong(n) )
.filter(n-> n%2 == 0)
.forEach(System.out::println);
}
}The code above generates the following result.
2
4End
description
List<String> list = Arrays.asList("Gza","Gzb","Gox","Elephant");
String max = list.stream().max(Comparator.comparing(String::valueOf)).get();
System.out.println("Max:"+ max);
String min = list.stream().min(Comparator.comparing(String::valueOf)).get();
System.out.println("Min:"+ min);
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