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In C++, a null pointer can be defined by as a null pointer constant is an integer constant expression with the value 0, like −int*p = 0;But in c, a null pointer can be defined by as a null pointer constant is an integer constant expression with the value 0 or such an expression cast to void*, like −Int *p = 0;;Orint*p = (void*) 0;In C++11 a keyword “nullptr” is used to represent nullpointer.int* ptr = nullptr;In CExample Live Demo#include int main() { int *p= NULL; //initialize the pointer as null. printf("The value of pointer is %u", p); ... Read More
Creating an exact copy of an existing object in the memory is known as cloning.The clone() method of the class java.lang.Object accepts an object as a parameter, creates and returns a copy of it (clones).In order to use this method, you need to make sure that your class implements the Cloneable interface.Example Live Demoimport java.util.Scanner; public class CloneExample implements Cloneable { private String name; private int age; public CloneExample(String name, int age){ this.name = name; this.age = age; } public void displayData(){ System.out.println("Name : "+this.name); ... Read More
The HTML DOM Select type property returns the value of the type attribute of drop-down list in an HTML document.SyntaxFollowing is the syntax −object.typeExampleLet us see an example of HTML DOM select type property − Live Demo html{ height:100%; } body{ text-align:center; color:#fff; background: radial-gradient( circle farthest-corner at 23.1% 64.6%, rgba(129, 125, 254, 1) 0%, rgba(111, 167, 254, 1) 90% ) no-repeat; height:100%; } p{ font-weight:700; font-size:1.1rem; } .drop-down{ ... Read More
To set single selection for JList, use DefaultListSelectionModel and set it to SINGLE_SELECTION:String values[]= { "One", "Two", "Three", "Four", "Five", "Six"}; JList list = new JList(values); list.setSelectionMode(DefaultListSelectionModel.SINGLE_SELECTION);The following is an example to set the selection mode for JList only for single selection: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"); SwingDemo s = new SwingDemo(); JPanel panel = new JPanel(); String values[]= { ... Read More
In C++, the inline keyword is used in different places. To create inline variables, or inline namespace, and as well as to create inline methods or functions.C++ inline function is powerful concept that is commonly used with classes. If a function is inline, the compiler places a copy of the code of that function at each point where the function is called at compile time.Any change to an inline function could require all clients of the function to be recompiled because compiler would need to replace all the code once again otherwise it will continue with old functionality.To inline a ... Read More
If a collection does not exist then MongoDB creates a collection in indexing part. The createdCollectionAutomatically tells that the operation created a collection.For our example, let us create a collection with an index −> db.createCollectionDemo.createIndex({"ClientCountryName":1});This will produce the following output −{ "createdCollectionAutomatically" : true, "numIndexesBefore" : 1, "numIndexesAfter" : 2, "ok" : 1 }Let us create a collection with documents −> db.createCollectionDemo.insertOne({"ClientName":"Larry", "ClientCountryName":"US"}); { "acknowledged" : true, "insertedId" : ObjectId("5cd2950be3526dbddbbfb612") }Following is the query to display all documents from a collection with the help of find() method −> db.createCollectionDemo.find().pretty();This will produce the following output ... Read More
Use the getPreviousSibling() method to get the previous sibling. Here, we are getting the previous sibling of child node “five” and displaying on Console −System.out.println("Get Previous Sibling = "+five.getPreviousSibling());The following is an example to get the previous sibling from a JTree −Examplepackage my; import javax.swing.JFrame; import javax.swing.JTree; import javax.swing.tree.DefaultMutableTreeNode; public class SwingDemo { public static void main(String[] args) throws Exception { JFrame frame = new JFrame("Demo"); DefaultMutableTreeNode node = new DefaultMutableTreeNode("Products"); DefaultMutableTreeNode node1 = new DefaultMutableTreeNode("Clothing (Product1 - P66778)"); DefaultMutableTreeNode node2 = new DefaultMutableTreeNode("Accessories (Product2 - P66779)"); ... Read More
To order with a custom rule, use the ORDER BY FIELD(). Let us first create a table −mysql> create table DemoTable ( Number int ); Query OK, 0 rows affected (0.55 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(1); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values(4); Query OK, 1 row affected (0.22 sec) mysql> insert into DemoTable values(2); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values(3); Query OK, 1 row affected (0.14 sec)Display all records from the table using select statement −mysql> ... Read More
The UncaughtExceptionHandler is an interface inside a Thread class. When the main thread is about to terminate due to an uncaught exception the java virtual machine will invoke the thread’s UncaughtExceptionHandler for a chance to perform some error handling like logging the exception to a file or uploading the log to the server before it gets killed. We can set a Default Exception Handler which will be called for the all unhandled exceptions. It is introduced in Java 5 Version.This Handler can be set by using the below static method of java.lang.Thread class.public static void setDefaultUncaughtExceptionHandler(Thread.UncaughtExceptionHandler ueh)We have to provide an implementation of the interface ... Read More
Creating an exact copy of an existing object in the memory is known as cloning.The clone() method of the class java.lang.Object accepts an object as a parameter, creates and returns a copy of it (clones).In order to use this method, you need to make sure that your class implements the Cloneable interface.Example Live Demoimport java.util.Scanner; public class CloneExample implements Cloneable { private String name; private int age; public CloneExample(String name, int age){ this.name = name; this.age = age; } public void displayData(){ System.out.println("Name : "+this.name); ... Read More