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To concatenate two columns, use CONCAT() function in MySQL. The syntax is as follows −select CONCAT(yourColumnName1, ' ', yourColumnName2) as anyVariableName from yourTableName;To understand the above concept, let us create a table. The query to create a table is as follows −mysql> create table concatenateTwoColumnsDemo −> ( −> StudentId int, −> StudentName varchar(200), −> StudentAge int −> ); Query OK, 0 rows affected (1.06 sec)Now you can insert some records in the table. The query to insert records is as follows −mysql> insert into concatenateTwoColumnsDemo values(1, 'Sam', 21); Query OK, 1 row affected (0.18 sec) ... Read More
A range of elements can be removed from a LinkedList by using the method java.util.LinkedList.clear() along with the method java.util.LinkedList.subList(). A program that demonstrates this is given as follows −Example Live Demoimport java.util.LinkedList; public class Demo { public static void main(String[] args) { LinkedList l = new LinkedList(); l.add("Clark"); l.add("Bruce"); l.add("Diana"); l.add("Wally"); l.add("Oliver"); System.out.println("The LinkedList is: ... Read More
Use Iterator class to fetch elements of TreeSet.Create a TreeSet and add elements to itTreeSet set = new TreeSet(); set.add("13"); set.add("11"); set.add("12"); set.add("16"); set.add("19"); set.add("23"); set.add("21"); set.add("20"); set.add("30");Now, to display the elements, use Iterator classIterator i = set.iterator(); while(i.hasNext()){ System.out.println(i.next()); }The following is an example that fetch elements of TreeSet using IterationExample Live Demoimport java.util.*; public class Demo { public static void main(String args[]){ TreeSet set = new TreeSet(); set.add("13"); set.add("11"); ... Read More
Bandwidth delay product is a measurement of how many bits can fill up a network link. It gives the maximum amount of data that can be transmitted by the sender at a given time before waiting for acknowledgment. Thus it is the maximum amount of unacknowledged data.MeasurementBandwidth delay product is calculated as the product of the link capacity of the channel and the round – trip delay time of transmission.The link capacity of a channel is the number of bits transmitted per second. Hence, its unit is bps, i.e. bits per second.The round – trip delay time is the sum ... Read More
A directory can be created with the required abstract path name using the method java.io.File.mkdir(). This method requires no parameters and it returns true on the success of the directory creation or false otherwise.A program that demonstrates this is given as follows −Example Live Demoimport java.io.File; public class Demo { public static void main(String[] args) { try { File file = new File("c:\demo1\"); file.createNewFile(); boolean flag = file.mkdir(); System.out.print("Directory created? " + flag); } catch(Exception e) { ... Read More
To convert string to date in MySQL, you can use STR_TO_DATE() function. The syntax is as follows −select str_to_date(‘StringValue’, '%d, %m, %Y') as anyVariableName;Apply the above syntax in the following query wherein, we have a string value −mysql> SELECT STR_TO_DATE('26, 11, 2018', '%d, %m, %Y');The following is the output −+--------------------------------------+ | STR_TO_DATE('26, 11, 2018', '%d, %m, %Y') | +--------------------------------------+ | 2018-11-26 | +--------------------------------------+ 1 row in set (0.00 sec)Let us see another example, to ... Read More
Use the containsValue() method to check if a given value exists or not in a HashMap.First, let us create a HashMap and add some elements −HashMap hm = new HashMap(); // Put elements to the map hm.put("Bag", new Integer(1100)); hm.put("Sunglasses", new Integer(2000)); hm.put("Frames", new Integer(800)); hm.put("Wallet", new Integer(700)); hm.put("Belt", new Integer(600));Now let us check whether a given value exist or not. Here, we are checking for the value “800” −hm.containsValue(800);The following is an example to check if a given value exists in a HashMap −Example Live Demoimport java.util.*; public class Demo { public static void main(String args[]) { ... Read More
The ceiling() method returns the least element greater than or equal to the given element i.e. 30 hereceiling(30)The following is an example to implement the ceiling method in JavaExample Live Demoimport java.util.NavigableSet; import java.util.TreeSet; public class Demo { public static void main(String[] args) { NavigableSet set = new TreeSet(); set.add(10); set.add(25); set.add(40); set.add(55); set.add(70); set.add(85); set.add(100); System.out.println("Returned Value = " + set.ceiling(30)); } }OutputReturned Value = 40
Use the remove() method to remove a value from TreeMap.Create a TreeMap first and add some elements −TreeMap m = new TreeMap(); m.put(1, "PHP"); m.put(2, "jQuery"); m.put(3, "JavaScript"); m.put(4, "Ruby"); m.put(5, "Java"); m.put(6, "AngularJS"); m.put(7, "ExpressJS");Now, let’s say you need to remove a value with key 5. For that, use the remove() method −Object ob = m.remove(5);The following is an example to remove a value from TreeMap −Example Live Demoimport java.util.*; public class Demo { public static void main(String args[]) { TreeMap m = new TreeMap(); m.put(1, "PHP"); m.put(2, "jQuery"); ... Read More
In computer networking, pipelining is the method of sending multiple data units without waiting for an acknowledgment for the first frame sent. Pipelining ensures better utilization of network resources and also increases the speed of delivery, particularly in situations where a large number of data units make up a message to be sent.Flow Diagram of Pipelined Data TransmissionThe following flow diagram depicts data transmission in a pipelined system versus that in a non-pipelined system. Here, pipelining is incorporated in the data link layer, and four data link layer frames are sequentially transmitted.Data Link Protocols that uses PipeliningTwo data link layer ... Read More