Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Class objects can be created in Java by using the new operator. A class is instantiated by the new operator by allocating memory for the object dynamically and then returning a reference for that memory. A variable is used to store the memory reference.A program that demonstrates this is given as follows:Example Live Democlass Student { int rno; String name; public Student(int r, String n) { rno = r; name = n; } void display() { System.out.println("Roll Number: " + rno); System.out.println("Name: " + ... Read More
You can execute insert if table is empty with the help of subquery. For that, work on not exists condition with subquery.The below syntax will work only when your table is empty. If your table is not empty then it will not insert the record. The syntax is as follows:INSERT INTO yourTableName(yourColumnName) SELECT ‘anyValue’ WHERE NOT EXISTS (SELECT *FROM yourTableName);To understand the above syntax, let us create a table. The query to create a table is as follows:mysql> create table ExecuteInsertDemo -> ( -> Name varchar(20) -> ); Query OK, 0 rows affected (0.67 sec)Let us insert ... Read More
Kubla Khan is one of the most famous poems written by Samuel Taylor Coleridge. Coleridge who was a Romantic poet and became immortal after writing this unique poem.Summary of 'Kubla Khan'The speaker starts by describing the setting of Emperor Kubla Khan's palace as a "pleasure dome." He tells us about a river that runs across the land and then flows through caves into the sea. He also describes the fertile land surrounding the palace. There is a vivid description of a nearby area all covered in streams, trees, and beautiful forests. He also describes how a river leaps and smashes ... Read More
This is not true that everyone leaves a job in frenzy. Sometimes things in personal and professional life go asymmetrical and one has to leave a job. However, champions know how and when to leave a job. Let’s know about it:The Gallop Poll happened in 2014 reveals that 68% of employees are not actively attached to their workplace. You will be surprised to know that many companies including MNCs have dissatisfied employees. Is being unhappy at work a reason to quit a job? Or Don't you consider leaving a job a personal failure?Seth Godin in his book ‘The Dip’ mentions, ... Read More
Stop – and – Wait protocol is data link layer protocol for transmission of frames over noiseless channels. It provides unidirectional data transmission with flow control facilities but without error control facilities.This protocol takes into account the fact that the receiver has a finite processing speed. If data frames arrive at the receiver’s end at a rate which is greater than its rate of processing, frames be dropped out. In order to avoid this, the receiver sends an acknowledgement for each frame upon its arrival. The sender sends the next frame only when it has received a positive acknowledgement from ... Read More
A class can be derived from the base class in Java by using the extends keyword. This keyword is basically used to indicate that a new class is derived from the base class using inheritance. It can also be said that it is used to extend the functionality of the class.A program that demonstrates this is given as follows:Example Live Democlass A { void funcA() { System.out.println("This is class A"); } } class B extends A { void funcB() { System.out.println("This is class B"); } } public class Demo { ... Read More
If your table name or column name are any reserved words then you need to use quotes around table name and column name in a MySQL query. You need to use backticks around table name and column name. The syntax is as follows:SELECT *FROM `table` where `where`=condition;Here is the query to create a table without quotes with reserved words. You will get an error since they are predefined reserved words. The error is as follows:mysql> create table table -> ( -> where int -> ); ERROR 1064 (42000): You have an error in your SQL syntax; check ... Read More
To load an image in table view cell we’ll go through a series of steps.Create a table view, table view cell and add an Image view to it.Assign a custom class to the cell we created.In the cell for row at method write the following lines of code.let cell = tblView.dequeueReusableCell(withIdentifier: "CustomCell") as! CustomCell return cellTo download the image we’ll create a function and embed that into an extension.func setImageFromUrl(ImageURL :String) { URLSession.shared.dataTask( with: NSURL(string:ImageURL)! as URL, completionHandler: { (data, response, error) -> Void in DispatchQueue.main.async { if let ... Read More
This example demonstrates how to verify enter number is phone number or not, using regex in android.Step 1 - Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.Step 2 - Add the following code to res/layout/activity_main.xml. In the above code, we have taken Edit text and text view. when the user clicks on text view, it will take data from edit text and valid the data.Step 3 - Add the following code to src/MainActivity.javapackage com.example.andy.myapplication; import android.os.Build; import android.os.Bundle; import android.support.annotation.RequiresApi; ... Read More
Parent class objects can be referred to using the super keyword in Java. It is usually used in the context of inheritance. A program that demonstrates the super keyword in Java is given as follows:Example Live Democlass A { int a; A(int x) { a = x; } } class B extends A { int b; B(int x, int y) { super(x); b = y; } void print() { System.out.println("Value of a: " + a); System.out.println("Value of b: " ... Read More