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Use typeof to find datatype of all the fields −typeof db.yourCollectionName.findOne().yourFieldName;Let us first create a collection with documents −> db.findDataTypeDemo.insertOne({"ClientName":"Chris", "isMarried":false}); { "acknowledged" : true, "insertedId" : ObjectId("5ccf2064dceb9a92e6aa1952") }Following is the query to display all documents from a collection with the help of find() method −> db.findDataTypeDemo.findOne();This will produce the following output −{ "_id" : ObjectId("5ccf2064dceb9a92e6aa1952"), "ClientName" : "Chris", "isMarried" : false }Following is the query to find datatype of a field in MongoDB −> typeof db.findDataTypeDemo.findOne().isMarried;This will produce the following output −BooleanHere is the query to get the data type of another field −> ... Read More
To determine when a Window is opened in Java, use the WindowListener, which is the listener interface for receiving window events..WindowListener listener = new WindowAdapter() { public void windowOpened(WindowEvent evt) { Frame frame = (Frame) evt.getSource(); System.out.println("Opened "+frame.getTitle()); } };Above, we have used the windowOpened() method, which is invoked when a window has been opened −public void windowOpened(WindowEvent evt) { Frame frame = (Frame) evt.getSource(); System.out.println("Opened "+frame.getTitle()); }The following is an example to determine when a frame or window is opened in Java −Examplepackage my; import java.awt.BorderLayout; import java.awt.Color; import ... Read More
Let us first create a collection with documents −> db.excludeIdDemo.insertOne({"StudentFirstName":"John", "StudentAge":21}); { "acknowledged" : true, "insertedId" : ObjectId("5cd701a56d78f205348bc632") } > db.excludeIdDemo.insertOne({"StudentFirstName":"Robert", "StudentAge":20}); { "acknowledged" : true, "insertedId" : ObjectId("5cd701af6d78f205348bc633") } > db.excludeIdDemo.insertOne({"StudentFirstName":"Chris", "StudentAge":24}); { "acknowledged" : true, "insertedId" : ObjectId("5cd701b86d78f205348bc634") }Following is the query to display all documents from a collection with the help of find() method −> db.excludeIdDemo.find();This will produce the following output −{ "_id" : ObjectId("5cd701a56d78f205348bc632"), "StudentFirstName" : "John", "StudentAge" : 21 } { "_id" : ObjectId("5cd701af6d78f205348bc633"), "StudentFirstName" : "Robert", "StudentAge" : 20 } { "_id" : ObjectId("5cd701b86d78f205348bc634"), "StudentFirstName" : "Chris", "StudentAge" ... Read More
The size attribute of the element is used to set the width of the input. The more the width would lead to a textbox with more width. You can set the size attribute for the following input types − text, search, email, password, tel and url.Following is the syntax −Above, size_num is the width of the input you need to set in numbers. The default is 20.Let us now see an example to implement the size attribute of the element −Example Live Demo Register Id − Password − ... Read More
When a class has two or more methods by the same name but different parameters, at the time of calling based on the parameters passed respective method is called (or respective method body will be bonded with the calling line dynamically). This mechanism is known as method overloading.Example Live Democlass Test{ public int division(int a, int b){ int result = a/b; return result; } public double division (float a, float b){ double result = ... Read More
The HTML DOM input number form property returns the reference of the form that contains the number input field in the HTML document.SyntaxFollowing is the syntax −object.formExampleLet us see an example of HTML DOM input number form property − Live Demo body{ text-align:center; background-color:#1b203a; color:#fff; } form{ margin:2.5rem auto; border:1px solid #fff; padding:2rem; ... Read More
The HTML DOM table Object represent the element of an HTML document.Let us see how to create table objectSyntaxFollowing is the syntax −document.createElement(“TABLE”);PropertiesFollowing are the properties of table object −PropertyExplanationcaptionIt returns element of a table in an HTML document.tFootIt returns element of a table in an HTML document.tHeadIt returns element of a table in an HTML document.MethodsFollowing are the methods of table object −MethodExplanationcreateCaption()It generates an empty element and adds it to the table.createTFoot()It generates an empty element and adds it to the table.createTHead()It generates an empty element and adds it to the ... Read More
The Location host property returns/sets the hostname and host port (if specified). Port might not get displayed if not explicitly specified.SyntaxFollowing is the syntax −Returning value of the host propertylocation.hostValue of the host property setlocation.host = hostname:hostExampleLet us see an example for Location host property − Live Demo Location host form { width:70%; margin: 0 auto; text-align: center; } * { padding: 2px; margin:5px; } input[type="button"] { border-radius: 10px; } Location-host Current URL: ... Read More
Here we will see how to get the memory usage statistics under Linux environment using C++.We can get all of the details from “/proc/self/stat” folder. Here we are taking the virtual memory status, and the resident set size.Example#include #include #include #include #include using namespace std; void mem_usage(double& vm_usage, double& resident_set) { vm_usage = 0.0; resident_set = 0.0; ifstream stat_stream("/proc/self/stat", ios_base::in); //get info from proc directory //create some variables to get info string pid, comm, state, ppid, pgrp, session, tty_nr; string tpgid, flags, minflt, cminflt, majflt, cmajflt; string ... Read More
CLOSE_CURSORS_AT_COMMIT is the constant value of the ResultSet interface representing the holdability value. If the ResultSet holdability is set to this value whenever you commit/save a transaction using the commit() method of the Connection interface, the ResultSet objects created in the current transaction (that are already opened) will be closed.Let us create a table with name MyPlayers in MySQL database using CREATE statement as shown below −CREATE TABLE MyPlayers( ID INT, First_Name VARCHAR(255), Last_Name VARCHAR(255), Date_Of_Birth date, Place_Of_Birth VARCHAR(255), Country VARCHAR(255), PRIMARY KEY (ID) );Now, we will insert 7 records in MyPlayers table ... Read More