In order to copy elements of ArrayList to another ArrayList, we use the Collections.copy() method. It is used to copy all elements of a collection into another.Declaration −The java.util.Collections.copy() method is declared as follows −public static void copy(List

In order to copy elements of ArrayList to Java Vector, we use the Collections.copy() method. It is used to copy all elements of a collection into another.Declaration −The java.util.Collections.copy() method is declared as follows −public static void copy(List

In order to sort elements in an ArrayList in Java, we use the Collections.sort() method in Java. This method sorts the elements available in the particular list of the Collection class in ascending order.Declaration −The java.util.Collections.sort() method is declared as follows −public static void sort(List list)where list is an object on which sorting needs to be performed.Let us see a program to sort elements in an ArrayList in Java −Example Live Demoimport java.util.*; public class Example {    public static void main (String[] args) {       List zoo = new ArrayList();       zoo.add("Zebra");       zoo.add("Lion"); ... Read More

An array can be easily printed by using the method java.util.Arrays.toString() in Java. This method returns a string representation of the array contents that is enclosed in square brackets. If the array is null, then this method returns null.A program that demonstrates this is given as follows −Example Live Demoimport java.util.Arrays; public class Demo {    public static void main(String args[]) {       String str[] = {"John", "Harry", "Sally", "Emma", "Peter"};       System.out.println("The array content is:");       System.out.println(Arrays.toString(str));    } }OutputThe array content is: [John, Harry, Sally, Emma, Peter]Now let us understand the above program.The ... Read More

In order to get a synchronized list from an ArrayList, we use the synchronizedList(List ) method in Java. The Collections.synchronizedList(List ) method accepts the ArrayList as an argument and returns a thread safe list.Declaration −The Collections.synchronizedList(List ) method is declared as follows −public static List synchronizedList(List list)Let us see a program to get a synchronized List from ArrayList −Example import java.util.*; public class Example { public static void main (String[] args) { List list = new ArrayList(); list.add("Hello"); ... Read More

One of the methods in the Timer class is the void schedule(TimerTask task, long delay, long period) method. This method schedules tasks for repeated fixed-delay execution, beginning after the specified delay.In fixed-delay execution, each execution is scheduled with respect to the original execution time of the preceding execution. If an execution is delayed for a particular reason (case in point, garbage collection), the subsequent executions will be delayed as well.Declaration −The java.util.Timer.schedule(TimerTask task, long delay, long period) is declared as follows −public void schedule(TimerTask task, long delay, long period)Here, task is the task to be scheduled, delay is the delay ... Read More

Binary search on a double array can be implemented by using the methodjava.util.Arrays.binarySearch(). This method returns the index of the required double element if it is available in the array, otherwise it returns (-(insertion point) - 1) where the insertion point is the position at which the element would be inserted into the array.A program that demonstrates this is given as follows −Example Live Demoimport java.util.Arrays; public class Demo {    public static void main(String[] args) {       double d_arr[] = { 5.2, 7.5, 9.7, 1.8, 4.0 };       Arrays.sort(d_arr);       System.out.print("The sorted array is: ... Read More

To check if a given String contains only unicode letters, digits or space, we use the isLetterOrDigit() and charAt() methods with decision making statements.The isLetterOrDigit(char ch) method determines whether the specific character (Unicode ch) is either a letter or a digit. It returns a boolean value, either true or false.Declaration −The java.lang.Character.isLetter() method is declared as follows −public static boolean isLetter(char ch)The charAt() method returns a character value at a given index. It belongs to the String class in Java. The index must be between 0 to length()-1.Declaration −The java.lang.String.charAt() method is declared as follows −public char charAt(int index)Let us ... Read More

In order to convert a Queue to a List in Java, we can create an LinkedList and pass the Queue as an argument in the parameterized constructor of an ArrayList. This can be done as follows −Queue q = new LinkedList(); List l = new ArrayList(q);The quickest way is used to LinkedList in the first place which can be used both as a List and a Queue. This can be done as follows −Queue q = new LinkedList(); List l = (List) q;Let us see a program to convert a queue to a list −Example Live Demoimport java.util.LinkedList; import java.util.List; import ... Read More

In order to roll a six sided die 6000 times in Java, we need to the nextInt() statement with decision making statements.The nextInt() method returns the next random integer value from this random number generator sequence.Declaration − The java.util.Random.nextInt() method is declared as follows −public int nextInt()Let us see a program to roll a six sided die 6000 times −Example Live Demoimport java.util.Random; public class Example {    public static void main(String args[]) {       Random rd = new Random(); // random number generator       int freq[] = new int[6]; // creating an array to compute frequency ... Read More