Let us implement the above syntax in order to find all documents in MongoDB with field name “StudentFirstName”. The query is as follows −> db.getCollectionNames().forEach(function(myCollectionName) { ...    var frequency = db[myCollectionName].find({"StudentFirstName": {$exists: true}}).count(); ...    if (frequency > 0) { ...       print(myCollectionName); ...    } ... ... Read More

Use aggregate framework along with $ifNull operator for this. The $concatArrays in aggregation is used to concatenate arrays. Let us first create a collection with documents −>db.concatenateArraysDemo.insertOne({"FirstSemesterSubjects": ["MongoDB", "MySQL", "Java"], "SecondSemesterSubjects":["C", "C++", ]}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd687707924bb85b3f4895c") } > db.concatenateArraysDemo.insertOne({"FirstSemesterSubjects":["C#", "Ruby", "Python"]}); {    "acknowledged" ... Read More

Searching based on locality of reference, depends upon the memory access pattern data elements are reallocated.Here linear searching method is used to search an element.AlgorithmBegin    int find(int *intarray, int n, int item)    intialize comparisons = 0    for i = 0 to n-1       Increase comparisons ... Read More

In this section we will see how to print a number 100 times in C. There are some constraints. We cannot use loops, recursions or macro expansions.To solve this problem we will use the setjump and longjump in C. The setjump() and longjump() is located at setjmp.h library. The syntax ... Read More

You can concatenate results with the help of forEach(). Let us first create a collection with documents −> db.concatenateDemo.insertOne({"Name":"John", "Age":21}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cc80dd88f9e6ff3eb0ce448") } > db.concatenateDemo.insertOne({"Name":"Carol", "Age":23}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cc80de18f9e6ff3eb0ce449") }Following is the query to display all documents ... Read More

To customize how a JTabbedPane looks, change its font style, font face, font size and the background and foreground colors.Let’s say the following is the JTabbedPane −JTabbedPane tabbedPane = new JTabbedPane();Now, let us customize the above created JTabbedPane −tabbedPane.setBackground(Color.orange); tabbedPane.setForeground(Color.white); Font font = new Font("Verdana", Font.CENTER_BASELINE, 18); tabbedPane.setFont(font);The following is ... Read More

Let us first create a collection with documents −> db.findByObjectIdDemo.insertOne({"ClientName":"Larry", "ClientAge":23}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd68cd657806ebf1256f11a") } > db.findByObjectIdDemo.insertOne({"ClientName":"Chris", "ClientAge":26}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd68cdc57806ebf1256f11b") } > db.findByObjectIdDemo.insertOne({"ClientName":"David", "ClientAge":38, "isMarried":true}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cd68cf657806ebf1256f11c") }Following is the ... Read More

This example demonstrate about How to group android notifications like whatsappStep 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

To update object at specific array index, use update() in MongoDB. Let us first create a collection with documents −> db.updateObjectDemo.insertOne( ...   { ...       id : 101, ...       "StudentDetails": ...       [ ...          [ ...     ... Read More

To set Line Border color and width, use the LineBorder. At first, set a panel wherein we need to set the line border −JPanel panel = new JPanel();Now, create a border and set on the panel created above −Border border = new LineBorder(Color.ORANGE, 4, true); panel.setBorder(border);The following is an example ... Read More