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 use JOptionPane with Array Elements in Java?
Let us first create and array and add elements −String[] sports = { "Football", "Cricket", "Squash", "Baseball", "Fencing", "Volleyball", "Basketball" };Now, set the above array elements to the JOptionPane −String res = (String) JOptionPane.showInputDialog(null, "Which sports you play the most?", "Sports", JOptionPane.PLAIN_MESSAGE, null, sports, sports[0]);Above, we have also set the initial value i.e. sports(0).The following is an example to use JOptionPane with array elements in Java −Examplepackage my; import javax.swing.JOptionPane; public class SwingDemo { public static void main(String[] args) { String[] sports = { "Football", "Cricket", "Squash", "Baseball", "Fencing", "Volleyball", "Basketball" }; ...
Read MoreHow to get or set the selection state of JCheckBox in Java
The following is an example to get or set the selection state of JCheckBox:Exampleimport java.awt.FlowLayout; import javax.swing.JCheckBox; import javax.swing.JFrame; public class SwingDemo extends JFrame { public SwingDemo() { setSize(500, 500); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); setLayout(new FlowLayout(FlowLayout.CENTER)); JCheckBox checkBox = new JCheckBox("Demo"); checkBox.setSelected(true); boolean sel = checkBox.isSelected(); if (sel) System.out.println("Check box selected!"); getContentPane().add(checkBox); } public static void main(String[] args) { new SwingDemo().setVisible(true); } }OutputSince the checkbox is selected by default, the following output would be visible in EclipseIDE:
Read MoreJava DatabaseMetaData supportsTransactions() method with example
The supportsTransactions() method of the DatabaseMetaData interface is used to determine whether the underlying database supports transactions.This method returns a boolean value which is −True, when the underlying database supports stored procedures.False, when the underlying database doesn't support stored procedures.To determine whether the underlying database supports stored procedures−Make sure your database is up and running.Register the driver using the registerDriver() method of the DriverManager class. Pass an object of the driver class corresponding to the underlying database.Get the connection object using the getConnection() method of the DriverManager class. Pass the URL the database and, user name, password of a user ...
Read MoreWhat are all the common undefined behaviours that a C++ programmer should know about?
In C++, there are some undefined behaviors. These are identified by doing some tasks in C++. There are no such direct definitions. These few things should be known to all of the programmers, who want to use C++ for different purposes.Here we will see some C++ Codes. and try to guess the results. The codes will generate some runtime errors.The Divide By Zero error is undefined.Example Code#include using namespace std; int main() { int x = 10, y = 0; int z = x / y; cout
Read MoreAdd multiple number input fields with JOptionPane and display the sum in Console with Java
At first, set multiple number input fields −JTextField text1 = new JTextField(10); JTextField text2 = new JTextField(10); JTextField text3 = new JTextField(10); JTextField text4 = new JTextField(10); JTextField text5 = new JTextField(10); JTextField text6 = new JTextField(10); JTextField text7 = new JTextField(10); JTextField text8 = new JTextField(10); panel.add(text1); panel.add(text2); panel.add(text3); panel.add(text4); panel.add(text5); panel.add(text6); panel.add(text7); panel.add(text8);Now, let us add the values of the multiple number input fields created above −System.out.println(Integer.parseInt(text1.getText()) + Integer.parseInt(text2.getText()) + Integer.parseInt(text3.getText())+ Integer.parseInt(text4.getText())+ Integer.parseInt(text5.getText())+ Integer.parseInt(text6.getText())+ Integer.parseInt(text7.getText())+ Integer.parseInt(text8.getText()));Above, we have displayed the sum in the Console.The following is an example to sum multiple number input fields with ...
Read MoreHow do I avoid the variable value in a MySQL stored procedure to change when records are updated?
We will create a stored procedure that does not change the variable value whenever the value is updated.Let us first create a table −mysql> create table DemoTable ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, Value int ); Query OK, 0 rows affected (0.63 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(Value) values(100); Query OK, 1 row affected (0.13 sec) Display all records from the table using select statement : mysql> select *from DemoTable;Output+----+-------+ | Id | Value | +----+-------+ | 1 | 100 | +----+-------+ 1 row ...
Read MoreWhat are the rules to be followed while making a variable static and final?
Static variables − Static variables are also known as class variables. You can declare a variable static using the keyword. Once you declare a variable static there would only be one copy of it in the class, regardless of how many objects are created from it.public static int num = 39;final − Once you declare a variable final you cannot reassign value to it. When you declare a variable of a class static and final we are making it constant.Rules to be followedInitialization is mandatory − It is not mandatory to initialize the instance variables of a class in java. ...
Read MoreHandle JCheckBox Events with an ItemListener in Java
Here, we have used ItemListener to handle JCheckBox events i.e. whenever any of the CheckBox is selected.For example; When any of the sports like Football CheckBox is checked, event is fired and a message is visible in the botton.The following is an example to handle JCheckBox events with an ItemListener:Exampleimport java.awt.*; import java.awt.event.*; import javax.swing.*; public class SwingDemo { private JFrame mainFrame; private JLabel headerLabel; private JLabel statusLabel; private JPanel controlPanel; public SwingDemo(){ prepareGUI(); } public static void main(String[] args){ SwingDemo swingControlDemo = new SwingDemo(); ...
Read MoreJava DatabaseMetaData supportsTransactionIsolationLevel() method with example
JDBC provides support 5 transaction isolation levels through Connection interface.TRANSACTION_NONE: It is represented by integer value 0 does not support transactions.TRANSACTION_READ_COMMITTED: It is represented by integer value 2 supports transactions allowing Non-Repeatable Reads and, Phantom Reads.TRANSACTION_READ_UNCOMMITTED: It is represented by integer value 1 supports transactions allowing Dirty Reads, Non-Repeatable Reads and, Phantom Reads.TRANSACTION_REPEATABLE_READ: It is represented by integer value 4 supports transactions allowing only Phantom Reads.TRANSACTION_SERIALIZABLE: It is represented by integer value 8 supports transactions with out allowing Dirty Reads, Non-Repeatable Reads and, Phantom Reads.The supportsTransactionIsolationLevel() method of the DatabaseMetaData interface is used to determine whether the underlying database supports ...
Read MoreHow to find string count of a particular id in a column using a MySQL query?
For this, use the CHAR_LENGTH() function in MySQL. Let us first create a table −mysql> create table DemoTable ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, Subject longtext ); Query OK, 0 rows affected (1.17 sec)Now you can insert some records in the table using insert command −mysql> insert into DemoTable(Subject) values('MySQL, MongoDB'); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable(Subject) values('MySQL, MongoDB'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable(Subject) values('MongoDB'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable(Subject) values('MySQL'); Query OK, 1 row affected (0.15 sec) Display all records from the table using select statement : mysql> select *from DemoTable;Output+----+---------------+ | Id | Subject | +----+---------------+ | 1 | MySQL, MongoDB | | 2 | MySQL, MongoDB | | ...
Read More