Different Ways of Copying an Array in Java

Maruthi Krishna
Updated on 02-Jul-2020 12:26:07

826 Views

In general, arrays are the containers that store multiple variables of the same datatype. These are of fixed size and the size is determined at the time of creation. Each element in an array is positioned by a number starting from 0. You can access the elements of an array using name and position as −System.out.println(myArray[3]); //Which is 1457 Creating an array in Java:In Java, arrays are treated as referenced types you can create an array using the new keyword similar to objects and populate it using the indices as −int myArray[] = new int[7]; myArray[0] = 1254; myArray[1] = ... Read More

Count Occurrences of Known Distinct Values in MySQL

AmitDiwan
Updated on 02-Jul-2020 12:25:57

223 Views

For this, you can use aggregate function SUM(). Let us first create a table −mysql> create table DemoTable636 (    StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY, StudentFirstName varchar(100) ); Query OK, 0 rows affected (0.51 sec)Insert some records in the table using insert command −mysql> insert into DemoTable636(StudentFirstName) values('John'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable636(StudentFirstName) values('Robert'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable636(StudentFirstName) values('Robert'); Query OK, 1 row affected (0.22 sec) mysql> insert into DemoTable636(StudentFirstName) values('Sam'); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable636(StudentFirstName) values('Mike'); Query OK, ... Read More

Create MySQL Function to Find Average of Values in a Column

AmitDiwan
Updated on 02-Jul-2020 12:25:11

394 Views

Let us first create a table −mysql> create table DemoTable638 (Name varchar(100), Marks int); Query OK, 0 rows affected (0.68 sec)Insert some records in the table using insert command −mysql> insert into DemoTable638 values('John', 67); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable638 values('John', 90); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable638 values('David', 99); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable638 values('John', 60); Query OK, 1 row affected (0.13 sec)Display all records from the table using select statement −mysql> select *from DemoTable638;This will produce the following output −+-------+-------+ | ... Read More

Different Ways to Iterate Over an Array in Java

Maruthi Krishna
Updated on 02-Jul-2020 12:21:33

19K+ Views

In general, arrays are the containers that store multiple variables of the same datatype. These are of fixed size and the size is determined at the time of creation. Each element in an array is positioned by a number starting from 0.You can access the elements of an array using name and position as −System.out.println(myArray[3]); //Which is 1457Creating an array in JavaIn Java, arrays are treated as referenced types you can create an array using the new keyword similar to objects and populate it using the indices as −int myArray[] = new int[7]; myArray[0] = 1254; myArray[1] = 1458; myArray[2] = ... Read More

Accessing Array Element with Index Greater Than Size in Java

Maruthi Krishna
Updated on 02-Jul-2020 12:20:04

3K+ Views

An array is a data structure/container/object that stores a fixed-size sequential collection of elements of the same type. The size/length of the array is determined at the time of creation.The position of the elements in the array is called as index or subscript. The first element of the array is stored at the index 0 and, the second element is at the index 1 and so on.Each element in an array is accessed using an expression which contains the name of the array followed by the index of the required element in square brackets.For example, if an array of 6 elements ... Read More

Pass Negative Number as Array Size in Java

Maruthi Krishna
Updated on 02-Jul-2020 12:18:45

3K+ Views

In general, arrays are the containers that store multiple variables of the same datatype. These are of fixed size and the size is determined at the time of creation. Each element in an array is positioned by a number starting from 0.You can access the elements of an array using name and position as −System.out.println(myArray[3]); //Which is 1457Creating an array in JavaIn Java, arrays are treated as referenced types you can create an array using the new keyword similar to objects and populate it using the indices as −int myArray[] = new int[7];While creating array in this way, you must ... Read More

Assign Array of 100 Elements to Array of 10 Elements in Java

Maruthi Krishna
Updated on 02-Jul-2020 12:14:32

3K+ Views

In general, arrays are the containers that store multiple variables of the same datatype. These are of fixed size and the size is determined at the time of creation. Each element in an array is positioned by a number starting from 0.You can access the elements of an array using name and position as −System.out.println(myArray[3]); //Which is 1457Creating an array in JavaIn Java, arrays are treated as referenced types you can create an array using the new keyword similar to objects and populate it using the indices as −int myArray[] = new int[7];While creating array in this way, you must specify ... Read More

Best Practices for Using Packages in Java

Maruthi Krishna
Updated on 02-Jul-2020 12:11:58

904 Views

You can create the .class files of all the Java classes and interfaces related to each other in one folder automatically by declaring them under same package. A package is nothing but a directory storing classes and interfaces of a particular concept.Creating a packageYou can create a package and add required classes/interfaces in it just by declaring the package on the top of the Class/Interface files using the keyword package as −Package package_name;ExampleFollowing Java program, demonstrates the declaration of a package in Java.package com.tutorialspoint.mypackage; public class Sample{    public void demo(){       System.out.println("This is a method of the ... Read More

Display All Databases in MySQL and Show All Tables for Each

AmitDiwan
Updated on 02-Jul-2020 12:00:13

550 Views

For this, you can use INFORMATION_SCHEMA. Following is the syntax −select my_schema.SCHEMA_NAME, group_concat(tbl.TABLE_NAME) from information_schema.SCHEMATA my_schema left join information_schema.TABLES tbl on my_schema.SCHEMA_NAME=tbl.TABLE_SCHEMA group by my_schema.SCHEMA_NAME;Let us implement the above syntax in order to show all databases in MySQL and for each database −mysql> select my_schema.SCHEMA_NAME, group_concat(tbl.TABLE_NAME)    from information_schema.SCHEMATA my_schema    left join information_schema.TABLES tbl on my_schema.SCHEMA_NAME=tbl.TABLE_SCHEMA group by my_schema.SCHEMA_NAME;This will produce the following output −+---------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | SCHEMA_NAME               | group_concat(tbl.TABLE_NAME)                                               ... Read More

Read a Single Character Using Scanner Class in Java

Maruthi Krishna
Updated on 02-Jul-2020 11:52:39

2K+ Views

From Java 1.5 Scanner class was introduced. This class accepts a File, InputStream, Path and, String objects, reads all the primitive data types and Strings (from the given source) token by token using regular expressions. By default, whitespace is considered as the delimiter (to break the data into tokens).Reading a character using the Scanner classScanner class provides nextXXX() (where xxx is int, float, boolean etc) methods which are used to read various primitive datatypes. But it never provides a method to read a single character.But, you still can read a single character using this class.The next() method of the Scanner ... Read More

Advertisements