Article Categories
- All Categories
-
Data Structure
-
Networking
-
RDBMS
-
Operating System
-
Java
-
MS Excel
-
iOS
-
HTML
-
CSS
-
Android
-
Python
-
C Programming
-
C++
-
C#
-
MongoDB
-
MySQL
-
Javascript
-
PHP
-
Economics & Finance
Articles on Trending Technologies
Technical articles with clear explanations and examples
How to insert an object in an ArrayList at a specific position in java?
The add() method of the ArrayList class helps you to add elements to an array list. It has two variants −add(E e) − This method accepts an object/elements as a parameter and adds the given element at the end of the list.public void add(int index, E element) − This method accepts an element and an integer value representing the position at which we need to insert it and inserts the specified element at the specified position in this list. Shifts the element currently at that position (if any) and any subsequent elements to the right (adds one to their indices).Therefore ...
Read MoreOperations on an Array in Data Structures
Here we will see some basic operations of array data structure. These operations are −TraverseInsertionDeletionSearchUpdateThe traverse is scanning all elements of an array. The insert operation is adding some elements at given position in an array, delete is deleting element from an array and update the respective positions of other elements after deleting. The searching is to find some element that is present in an array, and update is updating the value of element at given position. Let us see one C++ example code to get better idea.Example#include #include using namespace std; main(){ vector arr; //insert elements ...
Read MoreHow to avoid ConcurrentModificationException while iterating a collection in java?
When you are working with collection objects, while one thread is iterating over a particular collection object, if you try to add or remove elements from it, a ConcurrentModificationException will be thrown.Not only that, If you are iterating a collection object, add or remove elements to it and try to iterate its contents again it is considered that you are trying to access the collection object using multiple threads and ConcurrentModificationException is thrown.Exampleimport java.util.ArrayList; import java.util.Iterator; public class OccurenceOfElements { public static void main(String args[]) { ArrayList list = new ArrayList(); //Instantiating ...
Read MoreCheck if a number has bits in alternate pattern - Set-2 O(1) Approach in C++
Let us consider we have an integer n. The problem is to check, whether this integer has alternate patterns in its binary equivalent or not. The alternate pattern means 101010….The approach is like: calculate num = n XOR (n >> 1), now if all bits of num is 1, then the num has alternating patterns.Example#include #include using namespace std; bool isAllBitSet(int n){ if (((n + 1) & n) == 0) return true; return false; } bool hasAlternatePattern(unsigned int n) { unsigned int num = n ^ (n >> 1); return isAllBitSet(num); } int main() { unsigned int number = 42; if(hasAlternatePattern(number)) cout
Read MoreCheck if a number is a Krishnamurthy Number or not in C++
Here we will see how to check a number is Krishnamurty number or not. A number is Krishnamurty number, if the sum of the factorial of each digit is the same as the number. For example, if a number is 145, then sum = 1! + 4! + 5! = 1 + 24 + 120 = 145. So this is a Krishnamurty number, The logic is simple, we have to find the factorial of each number, and find the sum, then if that is the same as a given number, the number is Krishnamurty number. Let us see the code ...
Read MoreCheck if a number is divisible by 23 or not in C++
Here we will see one program, that can check whether a number is divisible by 23 or not. Suppose a number 1191216 is given. This is divisible by 23.To check the divisibility, we have to follow this rule −Extract the last digit of the number/truncated number every timeadd 7 * (last digit of the number calculated previous) to the truncated numberRepeat these steps as long as necessary.17043, so 1704 + 7*3 = 1725 1725, so 172 + 7 * 5 = 207 207, this is 9 * 23, so 17043 is divisible by 23.Example#include #include using namespace std; ...
Read MoreBinary Tree Traversals in Data Structures
In this section we will see different traversal algorithms to traverse keys present in binary search tree. These traversals are Inorder traversal, Preorder traversal, Postorder traversal and the level order traversal.Suppose we have one tree like this −The Inorder traversal sequence will be like − 5 8 10 15 16 20 23The Preorder traversal sequence will be like − 10 5 8 16 15 20 23The Postorder traversal sequence will be like − 8 5 15 23 20 16 10The Level-order traversal sequence will be like − 10, 5, 16, 8, 15, 20, 23AlgorithminorderTraverse(root): Begin if root is not ...
Read MoreWhat is ArrayStoreException in Java?
When you have created an array of a particular data type with fixed size and populate it if you store a value other than its datatype an ArrayStoreException is thrown at the run time.ExampleIn the following Java program, we are creating an Integer array and trying to store a double value in it.import java.util.Arrays; public class ArrayStoreExceptionExample { public static void main(String args[]) { Number integerArray[] = new Integer[3]; integerArray[0] = 12548; integerArray[1] = 36987; integerArray[2] = 555.50; integerArray[3] = 12548; ...
Read MoreCheck if a number is divisible by 41 or not in C++
Here we will see one program, that can check whether a number is divisible by 41 or not. Suppose a number 104413920565933 is given. This is divisible by 41.To check the divisibility, we have to follow this rule −Extract the last digit of the number/truncated number every timesubtract 4 * (last digit of the number calculated previous) to the truncated numberRepeat these steps as long as necessary.30873, so 3087 - 4*3 = 3075 3075, so 307 - 4 * 5 = 287 287, so 28 – 4 * 7 = 0 So, 30873 is divisible by 41.Example#include #include ...
Read MoreWhat is meant by re-throwing exceptions in Java?
When an exception is cached in a catch block, you can re-throw it using the throw keyword (which is used to throw the exception objects).While re-throwing exceptions you can throw the same exception as it is without adjusting it as −try { int result = (arr[a])/(arr[b]); System.out.println("Result of "+arr[a]+"/"+arr[b]+": "+result); } catch(ArithmeticException e) { throw e; }Or, wrap it within a new exception and throw it. When you wrap a cached exception within another exception and throw it, it is known as exception chaining or, exception wrapping, by doing this you can adjust your exception, throwing a ...
Read More