To query null value in MongoDB, use $ne operator. Let us first create a collection with documents −> db.queryingNullDemo.insertOne( ...    { ...       "StudentName":"Larry", ...       "StudentDetails": ...       { ...          "StudentAge":21, ...          "StudentSubject":"MongoDB" ... ... Read More

Here we will see how to compare two floating point data or two double data using C or C++. The floating point / double comparison is not similar to the integer comparison.To compare two floating point or double values, we have to consider the precision in to the comparison. For ... Read More

Let us first create a collection with documents −> db.findOneWorkingDemo.insertOne({"ClientId":1, "ClientName":"Larry", "ClientAge":26}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd7c1716d78f205348bc64d") } > db.findOneWorkingDemo.insertOne({"ClientId":2, "ClientName":"Chris", "ClientAge":28}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd7c17d6d78f205348bc64e") } > db.findOneWorkingDemo.insertOne({"ClientId":3, "ClientName":"Robert", "ClientAge":34}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd7c1896d78f205348bc64f") }Following ... Read More

To query for multiple parameters in MongoDB, you can use the dot(.) notation. Let us first create a collection with documents −> db.multipleParametersDemo.insertOne( ...    { ...       "CustomerName" : "Larry", ...       "CustomerDetails" : [ ...          { ...       ... Read More

To set the background color of a single tab, use the setBackgroundAt() method. This gives an option to mention the index and the color. The index here is the index of the specific tab you want to color.Let us first create a JTabbedPane −JTabbedPane tabbedPane = new JTabbedPane();Now, set the ... Read More

PointersPointer variables are used to store the address of variable.SyntaxType *pointer;InitializationType *pointer; Pointer=variable name;ReferencesWhen a parameter is declared as reference, it becomes an alternative name for an existing parameter.SyntaxType &newname=existing name;InitializationType &pointer; Pointer=variable name;The main differences between pointers and reference parameters are −References are used to refer an existing variable ... Read More

The Copy initialization can be done using the concept of copy constructor. As we know that the constructors are used to initialize the objects. We can create our copy constructor to make a copy of some other object, or in other words, initialize current object with the value of another ... Read More

This example demonstrate about How to create a local Notifications in AndroidStep 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.     Step 3 ... 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,   ... Read More

In this section we will see the nullptr in C++. The nullptr denotes the pointer literals. It is a prvalue of type std::nullptr_t. It has implicit conversion property from nullptr to null pointer value of any pointer type and any pointer to member type. Let us see one program, to ... Read More