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The required value can be written at the current position of the buffer and then the current position is incremented using the method put() in the class java.nio.CharBuffer. This method requires a single parameter i.e. the value to be written in the buffer and it returns the buffer in which the value is inserted.A program that demonstrates this is given as follows −Example Live Demoimport java.nio.*; import java.util.*; public class Demo { public static void main(String[] args) { int n = 5; try { CharBuffer buffer = CharBuffer.allocate(5); ... Read More
The Copy constructor and the assignment operators are used to initialize one object to another object. The main difference between them is that the copy constructor creates a separate memory block for the new object. But the assignment operator does not make new memory space. It uses reference variable to point to the previous memory block.Copy Constructor (Syntax)classname (const classname &obj) { // body of constructor }Assignment Operator (Syntax)classname Ob1, Ob2; Ob2 = Ob1;Let us see the detailed differences between Copy constructor and Assignment Operator.Copy ConstructorAssignment OperatorThe Copy constructor is basically an overloaded constructorAssignment operator is basically ... Read More
To remove array element in MongoDB, you can use $pull and $in operator. The syntax is as follows:db.yourCollectionName.update({}, {$pull:{yourFirstArrayName:{$in:["yourValue"]}, yourSecondArrayName:"yourValue"}}, {multi:true} );To understand the above syntax, let us create a collection with document. The query to create a collection with document is as follows:>db.removeArrayElement.insertOne({"StudentName":"Larry", "StudentCoreSubject":["MongoD B", "MySQL", "SQL Server", "Java"], "StudentFavouriteTeacher":["John", "Marry", "Carol"]}); { "acknowledged" : true, "insertedId" : ObjectId("5c6ec9c46fd07954a4890688") }Display all documents from a collection with the help of find() method. The query is as follows:> db.removeArrayElement.find().pretty();The following is the output:{ "_id" : ObjectId("5c6ec9c46fd07954a4890688"), "StudentName" : "Larry", "StudentCoreSubject" : [ ... Read More
The out implicit object is an instance of a javax.servlet.jsp.JspWriter object and is used to send content in a response.The initial JspWriter object is instantiated differently depending on whether the page is buffered or not. Buffering can be easily turned off by using the buffered = 'false' attribute of the page directive.The JspWriter object contains most of the same methods as the java.io.PrintWriter class. However, JspWriter has some additional methods designed to deal with buffering. Unlike the PrintWriter object, JspWriter throws IOExceptions.Following table lists out the important methods that we will use to write boolean char, int, double, object, String, ... Read More
You can insert date values in SQL using the date datatype, The java.sql.Date class maps to the SQL DATE type.The PreparedStatement interface provides a method named setDate(). Using this you can insert date into a table. This method accepts two parameters −An integer representing the parameter index of the place holder (?) to which we need to set date value.a Date object representing the date value to be passed. The constructor of java.sql.Date class accepts a variable of long type representing the number of milliseconds from the epoch (standard base time I.e. January 1, 1970, 00:00:00 GMT).ExampleAssume we have created ... Read More
The difference between toArray() and toArray(T[] arr) of the CopyOnWriteArrayList class is that both the methods returns an array containing all of the elements in this collection, but the latter has some additional features i.e. the runtime type of the returned array is that of the specified array.The syntax is as followspublic T[] toArray(T[] arr)Here, the parameter arr is the array into which the elements of the list are to be stored.To work with CopyOnWriteArrayList class, you need to import the following packageimport java.util.concurrent.CopyOnWriteArrayList;The following is an example to implement CopyOnWriteArrayList class toArray() method in JavaExample Live Demoimport java.util.Arrays; import ... Read More
The year for a particular LocalDate can be obtained using the getYear() method in the LocalDate class in Java. This method requires no parameters and it returns the year which can range from MIN_YEAR to MAX_YEAR.A program that demonstrates this is given as followsExample Live Demoimport java.time.*; public class Demo { public static void main(String[] args) { LocalDate ld = LocalDate.parse("2019-02-14"); System.out.println("The LocalDate is: " + ld); System.out.println("The year is: " + ld.getYear()); } }OutputThe LocalDate is: 2019-02-14 The year is: 2019Now let us understand the above program.First the LocalDate ... Read More
You can use RAND() method for this. To retrieve a random row, use the following syntaxSELECT *FROM yourTableName ORDER BY RAND() LIMIT yourIntegerNumber;To understand the above syntax, let us create a table. The query to create a table is as followsmysql> create table gettingRandomRow -> ( -> CustomerId int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> CustomerName varchar(100) -> ); Query OK, 0 rows affected (0.45 sec)Insert some records in the table using insert command. The query is as follows −mysql> insert into gettingRandomRow(CustomerName) values('Chris'); Query OK, 1 row affected (0.14 sec) mysql> insert into gettingRandomRow(CustomerName) values('Robert'); ... Read More
You can get the size of a column of a table using the getPrecision() method of the ResultSetMetaData class.//Retrieving the ResultSetMetaData object ResultSetMetaData rsmd = rs.getMetaData(); //getting the column type int size_name = rsmd. getPrecision(3);Assume we have a table named employee_data in the database with description as shown below:+----------+--------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +----------+--------------+------+-----+---------+-------+ | id | int(11) | YES | | NULL | | | Name | varchar(255) | YES | ... Read More
Before getting into example, we should know, What is radio group in android. Radio Group contains group of radio buttons. Using radio buttons we can select and un select according to user requirements.This example demonstrate about how to use radio group 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. ... Read More