ArrayBlockingQueue Peek Method in Java

Chandu yadav
Updated on 30-Jul-2019 22:30:25

161 Views

The peek() method of the ArrayBlockingQueue class returns the head of this queue or null if this queue is empty.The syntax is as follows.public E peek()To work with ArrayBlockingQueue class, you need to import the following package.import java.util.concurrent.ArrayBlockingQueue;The following is an example to implement peek() method of Java ArrayBlockingQueue class.Example Live Demoimport java.util.concurrent.ArrayBlockingQueue; public class Demo {    public static void main(String[] args) throws InterruptedException {       ArrayBlockingQueue q = new ArrayBlockingQueue(10);       q.add(200);       q.add(310);       q.add(400);       q.add(450);       q.add(500);       q.add(550);       ... Read More

Check If a Field Contains a String in MongoDB

Smita Kapse
Updated on 30-Jul-2019 22:30:25

2K+ Views

You can use $regex operator to check if a field contains a string in MongoDB. The syntax is as follows −db.yourCollectionName.findOne({"yourFieldName":{$regex:".*yourValue.*"}});To understand the above concept, let us create a collection with the document. The query to create a collection with a document is as follows −> db.checkFieldContainsStringDemo.insertOne({"Id":1, "Name":"John"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5c77d762fc4e719b197a12ed") } > db.checkFieldContainsStringDemo.insertOne({"Id":2, "Name":"Johnson"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5c77d76bfc4e719b197a12ee") } > db.checkFieldContainsStringDemo.insertOne({"Id":3, "Name":"Carol"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5c77d774fc4e719b197a12ef") } > db.checkFieldContainsStringDemo.insertOne({"Id":4, "Name":"Mike"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5c77d77cfc4e719b197a12f0") } > db.checkFieldContainsStringDemo.insertOne({"Id":5, "Name":"Sam"}); ... Read More

Add to Existing Value in MySQL Column Using CONCAT Function

Chandu yadav
Updated on 30-Jul-2019 22:30:25

896 Views

To understand the concept, let us first create a demo table.mysql> create table addToExistingValueDemo    -> (    -> Instructor_Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> Instructor_Name varchar(30),    -> Instructor_TechnicalSubject text    -> ); Query OK, 0 rows affected (0.54 sec)Insert some records in the table using insert command. The query is as follows −mysql> insert into addToExistingValueDemo(Instructor_Name, Instructor_TechnicalSubject) values('John', 'C, C++'); Query OK, 1 row affected (0.15 sec) mysql> insert into addToExistingValueDemo(Instructor_Name, Instructor_TechnicalSubject) values('Carol', 'Java, Python'); Query OK, 1 row affected (0.18 sec) mysql> insert into addToExistingValueDemo(Instructor_Name, Instructor_TechnicalSubject) values('Bob', 'MySQL, SQL Server'); Query OK, 1 row ... Read More

Update MongoDB Collection Using toLower

Ankith Reddy
Updated on 30-Jul-2019 22:30:25

730 Views

There is a $toLower operator in MongoDB to be used as part of aggregate framework. But, we can also use the for loop to iterate over the specific field and update one by one.Let us first create a collection with documents> db.toLowerDemo.insertOne({"StudentId":101, "StudentName":"John"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5c9b1b4515e86fd1496b38bf") } > db.toLowerDemo.insertOne({"StudentId":102, "StudentName":"Larry"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5c9b1b4b15e86fd1496b38c0") } > db.toLowerDemo.insertOne({"StudentId":103, "StudentName":"CHris"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5c9b1b5115e86fd1496b38c1") } > db.toLowerDemo.insertOne({"StudentId":104, "StudentName":"ROBERT"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5c9b1b5a15e86fd1496b38c2") }Following is the query to display all documents from ... Read More

Append All Elements of Collection to ArrayList in Java

karthikeya Boyini
Updated on 30-Jul-2019 22:30:25

207 Views

Let us first create an ArrayList −ArrayListarr = new ArrayList(); arr.add("50"); arr.add("100"); arr.add("150"); arr.add("200"); arr.add("250"); arr.add("300");Now, let’s say we have another Collection as Vector −Vectorvector = new Vector(); vector.add("500"); vector.add("700"); vector.add("800"); vector.add("1000"); Append all the elements from the Vector to ArrayList: arr.addAll(vector);Example Live Demoimport java.util.ArrayList; import java.util.Vector; public class Demo {    public static void main(String[] args) {       ArrayListarr = new ArrayList();       arr.add("50");       arr.add("100");       arr.add("150");       arr.add("200");       arr.add("250");       arr.add("300");       Vectorvector = new Vector();       vector.add("500");   ... Read More

Order Randomly in MySQL with a Random Value Column

Krantik Chavan
Updated on 30-Jul-2019 22:30:25

267 Views

Let us first create a table. After that we will create a new random value column and order the record randomly:mysql> create table DemoTable (    StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY,    StudentName varchar(20) ); Query OK, 0 rows affected (0.57 sec)Following is the query to insert some records in the table using insert command:mysql> insert into DemoTable(StudentName) values('Larry'); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable(StudentName) values('Sam'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable(StudentName) values('Mike'); Query OK, 1 row affected (0.34 sec) mysql> insert into DemoTable(StudentName) values('Carol'); Query OK, 1 ... Read More

Meaning of const Last in a Function Declaration of a C++ Class

Anvi Jain
Updated on 30-Jul-2019 22:30:25

830 Views

Sometimes we can find the keyword ‘const’ present at the last of function declaration. So what does it mean?Using this one function can be made as constant. The idea of constant function is that, the function cannot be modified from the objects, where they are called. It is recommended to use the constant functions in our program.Let us see one example of constant function.Example#include using namespace std; class MyClass {    int value;    public:       MyClass(int val = 0) {          value = val;       }       int getVal() const ... Read More

What is SEO and Why It is Popular in Local Businesses

Sashi K
Updated on 30-Jul-2019 22:30:25

149 Views

SEO (Search Engine Optimisation) is meant to improve a website’s overall search-ability and visibility. Every business needs SEO, but why is SEO so important in local businesses?When it comes to digital marketing, local businesses SEO is the extremely important facet of internet marketing. Here is why ...Local SEO promotes your business's visibility when there are searches based on locations. Your business should get found when people are searching for the product's availability in that locality. These results include searches with certain Geo qualifiers like city, state, pin code, etc., and ‘near me’ searches. Based on your website's SEO, Google picks ... Read More

Create Unit Tuple in Java

karthikeya Boyini
Updated on 30-Jul-2019 22:30:25

181 Views

Java does not have any built-in tuple support by default. To use the tuple, we use the third-party library called Javatuples. Using this library, you can create a tuple of different sizes, starting from a single-element tuple, which is the Unit class, up to a ten-element tuple (Decade class). The following is the list of JavaTuples library classes: Unit: 1 element tuple Pair: 2 element tuple Triplet: 3 element tuple Quartet: 4 element tuple Quintet: 5 element tuple ... Read More

Print Local Time in Android SQLite

Anvi Jain
Updated on 30-Jul-2019 22:30:25

173 Views

Before getting into example, we should know what sqlite data base in android is. SQLite is an open source SQL database that stores data to a text file on a device. Android comes in with built in SQLite database implementation. SQLite supports all the relational database features. In order to access this database, you don't need to establish any kind of connections for it like JDBC, ODBC etc.This example demonstrate about How to find highest value in Android sqlite.Step 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to ... Read More

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