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Arrays can be compared using following ways in JavaUsing Arrays.equals(array1, array2) methods − This method iterates over each value of an array and compare using equals method.Using Arrays.deepEquals(array1, array2) methods − This method iterates over each value of an array and deep compare using any overridden equals method.Using == on array will not give the desired result and it will compare them as objects. See the example below for each of the comparison way.Example Live Demoimport java.util.Arrays; public class Tester{ public static void main(String[] args) { int[] array1 = {1, 2, 3}; int[] ... Read More
The reason behind it is that we will not receive any meaningful results from the comparisons when we use NULL with the comparison operators like ‘=’, ‘ Select 10 = NULL, 10< NULL, 10NULL; +-----------+----------+----------+ | 10 = NULL | 10< NULL | 10NULL | +-----------+----------+----------+ | NULL | NULL | NULL | +-----------+----------+----------+ 1 row in set (0.07 sec)The above result set is not meaningful in any sense.
java.lang.System.currentTimeMillis() method can be used to compute the time taken by a function in java. Trick is simple. Get the before time and after time using currentTimeMillis() where before time is the time when method is invoked and after time is when method has executed. See the example below −Example Live Demopublic class Tester{ public static void main(String[] args) { long startTime = System.currentTimeMillis(); longRunningMethod(); long endTime = System.currentTimeMillis(); System.out.println("Time taken: " + (endTime -startTime) + " ms"); } private static void longRunningMethod() { try { Thread.sleep(1000); } catch (InterruptedException e) { e.printStackTrace(); } } }OutputTime taken: 1000 ms
The current MySQL transaction will be committed and ended when any of the DDL statement such as CREATE or DROP databases, Create, ALTER or DROP tables or stored routines is executed in the middle of the current transaction. All the database changes made in the current transaction will be made permanent and cannot be rolled back.Examplemysql> START TRANSACTION; Query OK, 0 rows affected (0.00 sec) mysql> INSERT INTO MARKS Values(6, 'Manak', 'History', 70); Query OK, 1 row affected (0.26 sec) mysql> Create table student(id int, Name Varchar(10), ); Query OK, 0 rows affected (0.84 sec)As we can see ... Read More
This articles covers how to encode and decode JSON objects using Java programming language. Let's start with preparing the environment to start our programming with Java for JSON.EnvironmentBefore you start with encoding and decoding JSON using Java, you need to install any of the JSON modules available. For this tutorial we have downloaded and installed JSON.simple and have added the location of json-simple-1.1.1.jar file to the environment variable CLASSPATH.Mapping between JSON and Java entitiesJSON.simple maps entities from the left side to the right side while decoding or parsing, and maps entities from the right to the left while encoding.JSONJavastringjava.lang.Stringnumberjava.lang.Numbertrue|falsejava.lang.Booleannullnullarrayjava.util.Listobjectjava.util.MapOn decoding, ... Read More
The current transaction will be committed and ended if START TRANSACTION is executed in the middle of a current transaction. All the database changes made in the current transaction will be made permanent. This is called an implicit commit by a START TRANSACTION command.ExampleSuppose we have the following values in table ‘marks’mysql> select * from marks; +------+---------+-----------+-------+ | Id | Name | Subject | Marks | +------+---------+-----------+-------+ | 1 | Aarav | Maths | 50 | | 1 | Harshit | Maths | 55 | | 3 ... Read More
It can be understood with the help of the following example using the table named ‘Student’ having the following description −mysql> DESCRIBE Student; +--------+-------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +--------+-------------+------+-----+---------+-------+ | Name | varchar(20) | YES | | NULL | | | RollNo | int(11) | YES | | NULL | | | Grade | varchar(10) | YES | | NULL | | +--------+-------------+------+-----+---------+-------+ 3 rows in set ... Read More
With the help of the following built-in commands, MySQL can execute a query even if semicolon (;) terminator symbol is not used.egoWe can use this command by using \G option. It means to send the current statement to the server to be executed and display the result in vertical format. When we use \G and omitting semicolon(;) in a statement (single or multiple lines), MySQL determines the end of the statement as and when it encounters \G. Consider the example below −mysql> Select * from ratelist\G *************************** 1. row *************************** Sr: 1 Item: A Price: 502 *************************** 2. row ... Read More
An operating system is a construct that allows the user application programs to interact with the system hardware. Operating system by itself does not provide any function but it provides an atmosphere in which different applications and programs can do useful work.There are many problems that can occur while designing and implementing an operating system. These are covered in operating system design and implementation.Operating System Design GoalsIt is quite complicated to define all the goals and specifications of the operating system while designing it.The design changes depending on the type of the operating system i.e if it is batch system, ... Read More
“WITH ROLLUP” is a modifier that is used with GROUP BY clause. Mainly, it causes the summary output to include extra rows that represent higher-level summary operations.ExampleIn the example below, WITH ROLLUP modifier gave the summary output with total price value in the extra row.mysql> Select Item, SUM(Price) AS Price from ratelist Group by item WITH ROLLUP; +------+-------+ | Item | Price | +------+-------+ | A | 502 | | B | 630 | | C | 1005 | | h | 850 | | T | 250 | | NULL | 3237 | +------+-------+ 6 rows in set (0.00 sec)