Java lambda expressions w3schools example geeksforgeeks

Java lambda expressions w3schools example geeksforgeeks

I can see you're looking for examples of Java lambda expressions from W3Schools and GeeksforGeeks! Here they are:

W3Schools Example:

W3Schools provides a simple example of using a lambda expression to sort an array of strings based on their lengths. The code looks like this:

import java.util.Arrays;
import java.util.Comparator;
public class Main {
public static void main(String[] args) {
String[] arr = {"apple", "banana", "cherry", "date", "elderberry"};
Arrays.sort(arr, (s1, s2) -> Integer.compare(s1.length(), s2.length()));
System.out.println(Arrays.toString(arr));
}
}

In this example, the lambda expression (s1, s2) -> Integer.compare(s1.length(), s2.length()) is used as a comparator to sort the array of strings based on their lengths.

GeeksforGeeks Example:

GeeksforGeeks provides several examples of using lambda expressions in Java. One example is to use a lambda expression as a predicate (a function that takes an input and returns a boolean value) to filter out even numbers from a list:

import java.util.ArrayList;
import java.util.List;
public class Main {
public static void main(String[] args) {
List numbers = new ArrayList<>();
numbers.add(1);
numbers.add(2);
numbers.add(3);
numbers.add(4);
numbers.add(5);
List evenNumbers = numbers.stream()
.filter(x -> x % 2 == 0)
.collect(ArrayList::new, (list, x) -> list.add(x), ArrayList::addAll);
System.out.println(evenNumbers);
}
}

In this example, the lambda expression x -> x % 2 == 0 is used to filter out even numbers from the input list. The stream() method is used to create a stream from the list, and then the filter() method is used with the lambda expression as its predicate. Finally, the filtered list is collected into an ArrayList using the collect() method.

More Examples:

GeeksforGeeks also provides examples of using lambda expressions in more complex scenarios, such as:

import java.util.Arrays;
public class Main {
public static void main(String[] args) {
Integer[] array = {1, 2, 3, 4, 5, 6};
Arrays.sort(array);
System.out.println(Arrays.toString(array));
int target = 3;
int result = binarySearch(array, target);
if (result != -1)
System.out.println("Element found at index " + result);
else
System.out.println("Element not found");
}
public static int binarySearch(Integer[] array, int target) {
int low = 0;
int high = array.length - 1;
while (low <= high) {
int mid = low + ((high - low) / 2);
if (array[mid].equals(target))
return mid;
else if (array[mid] < target)
low = mid + 1;
else
high = mid - 1;
}
return -1;
}
}

import java.util.ArrayList;
import java.util.List;
public class Main {
public static void main(String[] args) {
List words = new ArrayList<>();
words.add("banana");
words.add("cherry");
words.add("apple");
words.sort((s1, s2) -> s1.compareTo(s2));
System.out.println(words);
}
}

These examples demonstrate the versatility and power of lambda expressions in Java, allowing developers to write concise, expressive code that is easy to read and maintain.

I hope this helps!

Java lambda as parameter

I'm happy to help!

In Java, a lambda expression is an anonymous function that can be passed as an argument to a method, returned from a method, or stored in a data structure. Lambda expressions are essentially single-method interfaces that you can implement without explicitly declaring the interface or its methods.

To use a lambda expression as a parameter, you need to define a functional interface (an interface with a single abstract method) and then pass an instance of that interface as a parameter to a method. Here's an example:

interface MyInterface {
void doSomething(String input);
}
public class Main {
public static void process(MyInterface mi) {
mi.doSomething("Hello, World!");
}
public static void main(String[] args) {
process(s -> System.out.println(s));
}
}

In this example, MyInterface is a functional interface with a single abstract method (doSomething()). The process() method takes an instance of MyInterface as a parameter and calls its doSomething() method. In the main() method, we create a lambda expression that implements MyInterface by printing out the input string, and then pass it to the process() method.

Lambda expressions can be used to simplify code and make it more concise. They are particularly useful when you need to pass a small, one-method interface as an argument to a method or return it from a method.

Here are some key features of lambda expressions:

Here are some benefits of using lambda expressions:

Overall, lambda expressions are a powerful tool in Java that can help you write more concise, readable, and expressive code.