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Set is an abstract data type in which each element has to be unique because the value of the element identifies it. The value of the element cannot be modified once it is added to the set, but it is possible to remove and add the modified value of that element.A Map is an associative container that store elements in a mapped fashion. Each element has a key value and a mapped value. No two mapped values can have the same key values.So, it is clear from above that, set contains the only key, and map contains a value with ... Read More
This example demonstrate about Uninstall APKs programmaticallyStep 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. In the above code, we have taken text view.Step 3 − Add the following code to src/MainActivity.java import android.app.Activity; import android.content.Intent; import android.net.Uri; import android.os.Bundle; import android.view.View; import android.widget.TextView; import android.widget.Toast; public class MainActivity extends Activity { TextView text; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); ... Read More
You can use LEFT() from MySQL to display some character from the entire value in MySQL. Following is the syntax:select left(yourColumnName ,200 ) AS anyAliasName from yourTableName;Let us first create a table:mysql> create table DemoTable (Paragraph longtext); Query OK, 0 rows affected (0.71 sec)Following is the query to insert records in the table using insert command:mysql> insert into DemoTable values('Introduction to Java, Introduction to C, Introduction to C++, Introduction to Spring, Introduction to Hibernate, Introduction to Python, Introduction to MySQL, Introduction to MongoDB, Introduction to SQL Server, Introduction to ASP.net, Introduction to JSF'); Query OK, 1 row affected (0.13 sec)Following ... Read More
A new IntBuffer with the content as a shared subsequence of the original IntBuffer can be created using the method slice() in the class java.nio.IntBuffer. This method returns the new IntBuffer that is read-only if the original buffer is read-only and direct if the original buffer is direct.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 { IntBuffer buffer1 = IntBuffer.allocate(n); buffer1.put(3); ... Read More
This example demonstrates How to print list values in random order 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. In the above code, we have taken name and record number as Edit text, when user click on save button it will store the data into arraylist. Click on ... Read More
The containsAll() method checks for all the elements in the specified collection. It returns TRUE if this collection has all the elements. The methods check for each element one by one to see if it's contained in this collection.The syntax is as follows −public boolean containsAll(Collection c)To work with AbstractCollection class in Java, import the following package −import java.util.AbstractCollection;The following is an example to implement AbstractCollection containsAll() method in Java −Example Live Demoimport java.util.ArrayList; import java.util.AbstractCollection; public class Demo { public static void main(String[] args) { AbstractCollection absCollection1 = new ArrayList(); absCollection1.add("These"); ... Read More
You can delete everything in a MongoDB database using dropDatabase() function. The syntax is as follows −use yourDatabaseName; db.dropDatabase();The above syntax will delete everything in a MongoDB database.To delete everything in a MongoDB database, let us first display all the databases from MongoDB. The query is as follows −> show dbsThe following is the output −use yourDatabaseName; admin 0.000GB config 0.000GB flighInformation 0.000GB local 0.000GB sample 0.000GB sampleDemo 0.000GB test 0.003GBNow we will delete everything from the database ‘flightInformation’.First, you need to switch the database to ‘flightInformation’. The query is as follows −> use flighInformation; switched to db flighInformationNow here ... Read More
Yes, it is possible to cast in a MongoDB query −db.yourCollectionName.find("this.yourFieldName >yourValue);To understand the concept, let us create a collection with the document. The query to create a collection with a document is as follows −> db.castingDemo.insertOne({"Amount":"200"}); { "acknowledged" : true, "insertedId" : ObjectId("5c947e874cf1f7a64fa4df42") } > db.castingDemo.insertOne({"Amount":"100"}); { "acknowledged" : true, "insertedId" : ObjectId("5c947e8e4cf1f7a64fa4df43") } > db.castingDemo.insertOne({"Amount":"110"}); { "acknowledged" : true, "insertedId" : ObjectId("5c947e944cf1f7a64fa4df44") } > db.castingDemo.insertOne({"Amount":"95"}); { "acknowledged" : true, "insertedId" : ObjectId("5c947e9d4cf1f7a64fa4df45") } > db.castingDemo.insertOne({"Amount":"85"}); { "acknowledged" : true, "insertedId" : ObjectId("5c947ea44cf1f7a64fa4df46") } > db.castingDemo.insertOne({"Amount":"75"}); { "acknowledged" ... Read More
Set the two Java dates:LocalDate date1 = LocalDate.of(2019, 3, 25); LocalDate date2 = LocalDate.of(2019, 4, 29);Now, get the difference between two dates with Period class between() method:Period p = Period.between(date1, date2);Now, get the years, month and days:p.getYears() p.getMonths() p.getDays()Exampleimport java.time.LocalDate; import java.time.Period; public class Demo { public static void main(String[] args) { LocalDate date1 = LocalDate.of(2019, 3, 25); LocalDate date2 = LocalDate.of(2019, 4, 29); System.out.println("Date 1 = "+date1); System.out.println("Date 2 = "+date2); Period p = Period.between(date1, date2); System.out.println("Period = "+p); ... Read More
For this, you can use INFORMATION_SCHEMA.COLUMNS as shown in the following syntax −SELECT *FROM (SELECT *FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME= 'yourTableName') anyAliasName;Let us first create a table:mysql> create table DemoTable ( StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY, StudentFirstName varchar(20), StudentLastName varchar(20), StudentAge int ); Query OK, 0 rows affected (1.51 sec)Here is the query to use `SHOW COLUMNS` as a valid data source −mysql> SELECT *FROM (SELECT *FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME= 'DemoTable')tbl;This will produce the following output −+---------------+--------------+-------------+------------------+------------------+----------------+-------------+-----------+--------------------------+------------------------+-------------------+---------------+--------------------+--------------------+-----------------+-------------+------------+----------------+---------------------------------+----------------+-----------------------+--------+ | TABLE_CATALOG | TABLE_SCHEMA | TABLE_NAME | COLUMN_NAME | ORDINAL_POSITION | COLUMN_DEFAULT | IS_NULLABLE | ... Read More