Please note, this is a STATIC archive of website www.tutorialspoint.com from 11 May 2019, cach3.com does not collect or store any user information, there is no "phishing" involved.
Tutorialspoint

Retain elements from a Collection in another Collection in Java

import java.util.ArrayList;
import java.util.List;
public class Demo {
	public static void main(String args[]) throws Exception {
		List<Integer>list = new ArrayList<Integer>();
		list.add(100);
		list.add(200);
		list.add(200);
		list.add(200);
		list.add(300);
		list.add(400);
		list.add(400);
		list.add(500);
		List <Integer>list2 = new ArrayList<Integer>();
		list2.add(100);
		list2.add(200);
		list2.add(300);
		list2.add(400);
		list.retainAll(list2);
		System.out.println("Resultant list = "+list);
	}
}

Remove all elements from a Collection in another Collection in Java

import java.util.ArrayList;
import java.util.List;
public class Demo {
	public static void main(String args[]) throws Exception {
		List<Integer>list = new ArrayList<Integer>();
		list.add(100);
		list.add(200);
		list.add(200);
		list.add(200);
		list.add(300);
		list.add(400);
		list.add(400);
		list.add(500);
		List <Integer>list2 = new ArrayList<Integer>();
		list2.add(100);
		list2.add(200);
		list2.add(300);
		list2.add(400);
		list.removeAll(list2);
		System.out.println("Resultant list = "+list);
	}
}

Java Program to insert all elements of other Collection

import java.util.ArrayList;
import java.util.Vector;
public class Demo {
	public static void main(String[] args) {
		ArrayList<String>arr = new ArrayList<String>();
		arr.add("50");
		arr.add("100");
		arr.add("150");
		arr.add("200");
		arr.add("250");
		arr.add("300");
		Vector<String>vector = new Vector<String>();
		vector.add("500");
		vector.add("700");
		vector.add("800");
		vector.add("1000");
		// gets added at index 3
		arr.addAll(3, vector);
		System.out.println("Result after append...");
		for (String str: arr)
		 System.out.println(str);
	}
}

Java Program to get previous and next index using ListIterator

import java.util.ArrayList;
import java.util.ListIterator;
public class Demo {
	public static void main(String[] args) {
		ArrayList<Integer>arrList = new ArrayList<Integer>();
		arrList.add(100);
		arrList.add(200);
		arrList.add(300);
		arrList.add(400);
		arrList.add(500);
		arrList.add(600);
		arrList.add(700);
		arrList.add(800);
		arrList.add(900);
		arrList.add(1000);
		System.out.println("ArrayList...");
		for (Integer i: arrList)
			System.out.println(i);
			ListIterator<Integer>iterator = arrList.listIterator();
			System.out.println("Previous Index =" + iterator.previousIndex());
			System.out.println("Next Index = " + iterator.nextIndex());
			iterator.next();
			System.out.println("Previous Index = " + iterator.previousIndex());
			System.out.println("Next Index =" + iterator.nextIndex());
			iterator.next();
			iterator.next();
			System.out.println("Previous Index = " + iterator.previousIndex());
			System.out.println("Next Index = " + iterator.nextIndex());
	}
}

Java Program to display sub-list of ArrayList

import java.util.ArrayList;
import java.util.List;
public class Demo {
	public static void main(String[] args) {
		ArrayList<String>arrayList = new ArrayList<String>();
		arrayList.add("100");
		arrayList.add("200");
		arrayList.add("300");
		arrayList.add("400");
		arrayList.add("500");
		arrayList.add("600");
		arrayList.add("700");
		arrayList.add("800");
		arrayList.add("900");
		arrayList.add("1000");
		System.out.println("ArrayList...");
		for (String s: arrayList)
			System.out.println(s);
			List<String>list = arrayList.subList(4, 8);
			System.out.println("SubList of ArrayList...");
			for (int i = 0; i<list.size(); i++)
				System.out.println(list.get(i));
	}
}

Program to get the number of hours in this duration

import java.time.Duration;
public class Demo {
	public static void main(String[] args) {
		Duration duration =  Duration.ofDays(25);
		System.out.println("Hours in 25 days = "+duration.toHours());
	}
}

Fetch elements with iterator in Java

import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
public class Demo {
	public static void main(String[] a) {
		List<String>list = Arrays.asList(new String[] { "P", "Q", "R", "S", "T", "U", "V", "W" });
		Iterator<String>i = list.iterator();
		System.out.println("Displaying elements...");
		while (i.hasNext()) {
			System.out.println(i.next());
		}
	}
}

Create Java Priority Queue to ignore duplicates

import java.util.HashSet;
import java.util.PriorityQueue;
public class Demo {
	public static void main(String[] args) {
		HashSet<Integer>set = new HashSet<>();
		set.add(100);
		set.add(150);
		set.add(250);
		set.add(300);
		set.add(250);
		set.add(500);
		set.add(600);
		set.add(500);
		set.add(900);
		PriorityQueue<Integer>queue = new PriorityQueue<>(set);
		System.out.println("Elements with no duplicates = "+queue);
	}
}

Create a read-only list in Java

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
public class Demo {
	public static void main(String args[]) throws Exception {
		List<String>list = new ArrayList<String>();
		list.add("A");
		list.add("B");
		list.add("C");
		list = Collections.unmodifiableList(list);
		// An exception is thrown since its a read-only list now
		list.add("D");
		list.add("E");
		list.add("F");
		System.out.println(list);
	}
}

Java Program to create a new list with values from existing list

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.function.Function;
import java.util.stream.Collectors;
public class Demo {
	public static void main(String args[]) {
		List<Employee>emp = Arrays.asList(new Employee("Jack", 29, "South"), new Employee("Tom", 24, "North"), new Employee("Harry", 35, "West"),new Employee("Katie", 32, "East"));
		List<String>res =  emp.stream().map(u ->u.displayEmpName()).collect(Collectors.toList());
		System.out.println("Employee Names = "+res);
	}
}
class Employee {
	private String emp_name;
	private int emp_age;
	private String emp_zone;
	public Employee(String emp_name, int emp_age, String emp_zone) {
		this.emp_name = emp_name;
		this.emp_age = emp_age;
		this.emp_zone = emp_zone;
	}
	public String displayEmpName() {
		return this.emp_name;
	}
}

Advertisements
Loading...

We use cookies to provide and improve our services. By using our site, you consent to our Cookies Policy.