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To set a spinner of dates, at first create a date object −Date today = new Date();Now, use SpinnerDateModel −JSpinner spinner2 = new JSpinner(new SpinnerDateModel(today, null, null, Calendar.MONTH));We will now consider a DateEditor, which is an editor for a JSpinner whose model is a SpinnerDateModel. Set the format for month here −JSpinner.DateEditor editor = new JSpinner.DateEditor(spinner2, "MM"); spinner2.setEditor(editor);The following is an example to set a spinner of date in Java −Examplepackage my; import java.awt.GridBagLayout; import java.util.Calendar; import java.util.Date; import javax.swing.*; public class SwingDemo { public static void main(String[] args) { JFrame frame = new JFrame("Spinner Demo"); ... Read More
For predefined selection, use the setSelectedIndex() method, wherein you need to set the index of the item you want to be visible first.Let’s say the following is our aComboBox with elements −Object[] sports = { "Football", "Cricket", "Squash", "Baseball", "Fencing", "Volleyball", "Basketball" }; JComboBox comboBox = new JComboBox(sports);Now, set the initial selection with the index of the item −comboBox.setSelectedIndex(3);The following is an example to set JOptionPane with predefined selection in Java −Examplepackage my; import java.awt.GridBagLayout; import javax.swing.JComboBox; import javax.swing.JOptionPane; import javax.swing.JPanel; public class SwingDemo { public static void main(String[] args) throws Exception { JPanel panel = ... Read More
Let us first create a table with one of the column as ID −mysql> create table DemoTable ( ID int, StudentName varchar(10), CountryName varchar(20) ); Query OK, 0 rows affected (0.70 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(0, 'David', 'AUS'); Query OK, 1 row affected (0.24 sec) mysql> insert into DemoTable values(3, 'Chris', 'UK'); Query OK, 1 row affected (0.27 sec) mysql> insert into DemoTable values(8, 'Carol', 'US'); Query OK, 1 row affected (0.26 sec) mysql> insert into DemoTable values(9, 'Sam', 'US'); Query OK, 1 row affected (0.14 ... Read More
The stack − All variables declared inside the function will take up memory from the stack. So, any local variable inside a function lives on the stack.The heap − This is unused memory of the program and can be used to allocate the memory dynamically when program runs. So If we want something to live longer than the function that declared it, we must allocate it on the heap.Exampleint main() { int a; //get memory allocated on stack. int *ptr=new int[7]; //memory for 7 integers allocated on heap. }The main issue in heap memory is fragmentation whereas memory ... Read More
Java provides various datatypes to store various data values. It provides 7 primitive datatypes (stores single values) namely, boolean, byte, char, short, int, long, float, double and, reference datatypes (arrays and objects).Type Casting/type conversion −Converting one primitive datatype into another is known as type casting (type conversion) in Java. You can cast the primitive datatypes in two ways namely, Widening and, Narrowing.Narrowing − Converting a higher datatype to a lower datatype is known as narrowing. In this case the casting/conversion is not done automatically, you need to convert explicitly using the cast operator “( )” explicitly. Therefore, it is known ... Read More
Here we will see the asin() method for the complex numbers. The complex numbers can be used using complex header file. In that header file the asin () function is also present. This is complex version of normal asin () function. This is used to find complex arc sine of a complex number.This function takes a complex number as input parameter, and returns the arc sine as output. Let us see one example to get the idea.Example Live Demo#include #include using namespace std; int main() { complex c1(5, 2); //asin() function for complex number cout
To add JList to Scroll pane in Java, use JScrollPane:JList list = new JList(sports); JScrollPane scrollPane = new JScrollPane(list);After that set it to Container:Container contentPane = frame.getContentPane(); contentPane.add(scrollPane, BorderLayout.CENTER);The following is an example to add JList to Scroll pane:Examplepackage my; import java.awt.event.*; import java.awt.*; import javax.swing.*; class SwingDemo extends JFrame { static JFrame frame; static JList list; public static void main(String[] args) { frame = new JFrame("JList Demo"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); String sports[]= {"Tennis", "Archery", "Football", "Fencing", "Cricket", "Squash", "Hockey", "Rugby"}; list = new JList(sports); ... Read More
To add libraries in Visual Studio 2012, there are two different methods. The first one is manual method. The second one is adding libraries from code.Let us see the manual method first.To add some library, we have to follow these five steps −Add the #include statements necessary files with proper declarations. For example −#include “library.h”Add the include directory for the compiler look up;Go to the Configuration Properties/VC++ Directories/Include DirectoriesThen click and edit, and add new entryAdd one library directory for *.lib files:Go to project (on top bar) -> properties -> Configuration Properties -> VC++ Directories -> Library Directories, then click ... Read More
The getNumeric() method of the Connection interface retrieves the list of math functions supported by the current database. The names returned by this method are the Open CLI math function names.This method returns a String value holding the list of functions separated by commas (", ").To get the list of the numeric functions supported by the underlying database −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 ... Read More
You need to use $set operator along with upsert:true. Let us first create a collection with documents −> db.updateWithUpsertDemo.insertOne({"StudentFirstName":"John", "StudentAge":21}); { "acknowledged" : true, "insertedId" : ObjectId("5cd2a61c345990cee87fd890") } > db.updateWithUpsertDemo.insertOne({"StudentFirstName":"Larry", "StudentAge":23}); { "acknowledged" : true, "insertedId" : ObjectId("5cd2a624345990cee87fd891") } > db.updateWithUpsertDemo.insertOne({"StudentFirstName":"David", "StudentAge":24}); { "acknowledged" : true, "insertedId" : ObjectId("5cd2a62c345990cee87fd892") }Following is the query to display all documents from a collection with the help of find() method −> db.updateWithUpsertDemo.find().pretty();This will produce the following output −{ "_id" : ObjectId("5cd2a61c345990cee87fd890"), "StudentFirstName" : "John", "StudentAge" : 21 } { "_id" : ObjectId("5cd2a624345990cee87fd891"), "StudentFirstName" ... Read More