- Java online compiler
- Taking inputs (stdin)
- Adding dependencies
- About Java
- Syntax help
- Variables
- Loops
- 1. If Else:
- 2. Switch:
- 3. For:
- 4. While:
- 5. Do-While:
- Classes and Objects
- How to create a Class:
- Example:
- How to create a Object:
- How to define methods in a class:
- Collections
- Advantages:
- Java online compiler
- Taking inputs (stdin)
- Adding dependencies
- About Java
- Syntax help
- Variables
- Loops
- 1. If Else:
- 2. Switch:
- 3. For:
- 4. While:
- 5. Do-While:
- Classes and Objects
- How to create a Class:
- Example:
- How to create a Object:
- How to define methods in a class:
- Collections
- Advantages:
- Java online compiler
- Taking inputs (stdin)
- Adding dependencies
- About Java
- Syntax help
- Variables
- Loops
- 1. If Else:
- 2. Switch:
- 3. For:
- 4. While:
- 5. Do-While:
- Classes and Objects
- How to create a Class:
- Example:
- How to create a Object:
- How to define methods in a class:
- Collections
- Advantages:
Java online compiler
Write, Run & Share Java code online using OneCompiler’s Java online compiler for free. It’s one of the robust, feature-rich online compilers for Java language, running the Java LTS version 17. Getting started with the OneCompiler’s Java editor is easy and fast. The editor shows sample boilerplate code when you choose language as Java and start coding.
Taking inputs (stdin)
OneCompiler’s Java online editor supports stdin and users can give inputs to the programs using the STDIN textbox under the I/O tab. Using Scanner class in Java program, you can read the inputs. Following is a sample program that shows reading STDIN ( A string in this case ).
import java.util.Scanner; class Input < public static void main(String[] args) < Scanner input = new Scanner(System.in); System.out.println("Enter your name: "); String inp = input.next(); System.out.println("Hello, " + inp); >>Adding dependencies
OneCompiler supports Gradle for dependency management. Users can add dependencies in the build.gradle file and use them in their programs. When you add the dependencies for the first time, the first run might be a little slow as we download the dependencies, but the subsequent runs will be faster. Following sample Gradle configuration shows how to add dependencies
apply plugin:'application' mainClassName = 'HelloWorld' run < standardInput = System.in >sourceSets < main < java < srcDir './' >> > repositories < jcenter() >dependencies < // add dependencies here as below implementation group: 'org.apache.commons', name: 'commons-lang3', version: '3.9' >About Java
Java is a very popular general-purpose programming language, it is class-based and object-oriented. Java was developed by James Gosling at Sun Microsystems ( later acquired by Oracle) the initial release of Java was in 1995. Java 17 is the latest long-term supported version (LTS). As of today, Java is the world’s number one server programming language with a 12 million developer community, 5 million students studying worldwide and it’s #1 choice for the cloud development.
Syntax help
Variables
short x = 999; // -32768 to 32767 int x = 99999; // -2147483648 to 2147483647 long x = 99999999999L; // -9223372036854775808 to 9223372036854775807 float x = 1.2; double x = 99.99d; byte x = 99; // -128 to 127 char x = 'A'; boolean x = true;Loops
1. If Else:
When ever you want to perform a set of operations based on a condition If-Else is used.
if(conditional-expression) < // code >else < // code >2. Switch:
Switch is an alternative to If-Else-If ladder and to select one among many blocks of code.
3. For:
For loop is used to iterate a set of statements based on a condition. Usually for loop is preferred when number of iterations is known in advance.
for(Initialization; Condition; Increment/decrement) < //code >4. While:
While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.
5. Do-While:
Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.
Classes and Objects
Class is the blueprint of an object, which is also referred as user-defined data type with variables and functions. Object is a basic unit in OOP, and is an instance of the class.
How to create a Class:
class keyword is required to create a class.
Example:
How to create a Object:
How to define methods in a class:
public class Greeting < static void hello() < System.out.println("Hello.. Happy learning!"); >public static void main(String[] args) < hello(); >>Collections
Collection is a group of objects which can be represented as a single unit. Collections are introduced to bring a unified common interface to all the objects.
Collection Framework was introduced since JDK 1.2 which is used to represent and manage Collections and it contains:
This framework also defines map interfaces and several classes in addition to Collections.
Advantages:
- High performance
- Reduces developer’s effort
- Unified architecture which has common methods for all objects.
Java online compiler
Write, Run & Share Java code online using OneCompiler’s Java online compiler for free. It’s one of the robust, feature-rich online compilers for Java language, running the Java LTS version 17. Getting started with the OneCompiler’s Java editor is easy and fast. The editor shows sample boilerplate code when you choose language as Java and start coding.
Taking inputs (stdin)
OneCompiler’s Java online editor supports stdin and users can give inputs to the programs using the STDIN textbox under the I/O tab. Using Scanner class in Java program, you can read the inputs. Following is a sample program that shows reading STDIN ( A string in this case ).
import java.util.Scanner; class Input < public static void main(String[] args) < Scanner input = new Scanner(System.in); System.out.println("Enter your name: "); String inp = input.next(); System.out.println("Hello, " + inp); >>Adding dependencies
OneCompiler supports Gradle for dependency management. Users can add dependencies in the build.gradle file and use them in their programs. When you add the dependencies for the first time, the first run might be a little slow as we download the dependencies, but the subsequent runs will be faster. Following sample Gradle configuration shows how to add dependencies
apply plugin:'application' mainClassName = 'HelloWorld' run < standardInput = System.in >sourceSets < main < java < srcDir './' >> > repositories < jcenter() >dependencies < // add dependencies here as below implementation group: 'org.apache.commons', name: 'commons-lang3', version: '3.9' >About Java
Java is a very popular general-purpose programming language, it is class-based and object-oriented. Java was developed by James Gosling at Sun Microsystems ( later acquired by Oracle) the initial release of Java was in 1995. Java 17 is the latest long-term supported version (LTS). As of today, Java is the world’s number one server programming language with a 12 million developer community, 5 million students studying worldwide and it’s #1 choice for the cloud development.
Syntax help
Variables
short x = 999; // -32768 to 32767 int x = 99999; // -2147483648 to 2147483647 long x = 99999999999L; // -9223372036854775808 to 9223372036854775807 float x = 1.2; double x = 99.99d; byte x = 99; // -128 to 127 char x = 'A'; boolean x = true;Loops
1. If Else:
When ever you want to perform a set of operations based on a condition If-Else is used.
if(conditional-expression) < // code >else < // code >2. Switch:
Switch is an alternative to If-Else-If ladder and to select one among many blocks of code.
3. For:
For loop is used to iterate a set of statements based on a condition. Usually for loop is preferred when number of iterations is known in advance.
for(Initialization; Condition; Increment/decrement) < //code >4. While:
While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.
5. Do-While:
Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.
Classes and Objects
Class is the blueprint of an object, which is also referred as user-defined data type with variables and functions. Object is a basic unit in OOP, and is an instance of the class.
How to create a Class:
class keyword is required to create a class.
Example:
How to create a Object:
How to define methods in a class:
public class Greeting < static void hello() < System.out.println("Hello.. Happy learning!"); >public static void main(String[] args) < hello(); >>Collections
Collection is a group of objects which can be represented as a single unit. Collections are introduced to bring a unified common interface to all the objects.
Collection Framework was introduced since JDK 1.2 which is used to represent and manage Collections and it contains:
This framework also defines map interfaces and several classes in addition to Collections.
Advantages:
- High performance
- Reduces developer’s effort
- Unified architecture which has common methods for all objects.
Java online compiler
Write, Run & Share Java code online using OneCompiler’s Java online compiler for free. It’s one of the robust, feature-rich online compilers for Java language, running the Java LTS version 17. Getting started with the OneCompiler’s Java editor is easy and fast. The editor shows sample boilerplate code when you choose language as Java and start coding.
Taking inputs (stdin)
OneCompiler’s Java online editor supports stdin and users can give inputs to the programs using the STDIN textbox under the I/O tab. Using Scanner class in Java program, you can read the inputs. Following is a sample program that shows reading STDIN ( A string in this case ).
import java.util.Scanner; class Input < public static void main(String[] args) < Scanner input = new Scanner(System.in); System.out.println("Enter your name: "); String inp = input.next(); System.out.println("Hello, " + inp); >>Adding dependencies
OneCompiler supports Gradle for dependency management. Users can add dependencies in the build.gradle file and use them in their programs. When you add the dependencies for the first time, the first run might be a little slow as we download the dependencies, but the subsequent runs will be faster. Following sample Gradle configuration shows how to add dependencies
apply plugin:'application' mainClassName = 'HelloWorld' run < standardInput = System.in >sourceSets < main < java < srcDir './' >> > repositories < jcenter() >dependencies < // add dependencies here as below implementation group: 'org.apache.commons', name: 'commons-lang3', version: '3.9' >About Java
Java is a very popular general-purpose programming language, it is class-based and object-oriented. Java was developed by James Gosling at Sun Microsystems ( later acquired by Oracle) the initial release of Java was in 1995. Java 17 is the latest long-term supported version (LTS). As of today, Java is the world’s number one server programming language with a 12 million developer community, 5 million students studying worldwide and it’s #1 choice for the cloud development.
Syntax help
Variables
short x = 999; // -32768 to 32767 int x = 99999; // -2147483648 to 2147483647 long x = 99999999999L; // -9223372036854775808 to 9223372036854775807 float x = 1.2; double x = 99.99d; byte x = 99; // -128 to 127 char x = 'A'; boolean x = true;Loops
1. If Else:
When ever you want to perform a set of operations based on a condition If-Else is used.
if(conditional-expression) < // code >else < // code >2. Switch:
Switch is an alternative to If-Else-If ladder and to select one among many blocks of code.
3. For:
For loop is used to iterate a set of statements based on a condition. Usually for loop is preferred when number of iterations is known in advance.
for(Initialization; Condition; Increment/decrement) < //code >4. While:
While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.
5. Do-While:
Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.
Classes and Objects
Class is the blueprint of an object, which is also referred as user-defined data type with variables and functions. Object is a basic unit in OOP, and is an instance of the class.
How to create a Class:
class keyword is required to create a class.
Example:
How to create a Object:
How to define methods in a class:
public class Greeting < static void hello() < System.out.println("Hello.. Happy learning!"); >public static void main(String[] args) < hello(); >>Collections
Collection is a group of objects which can be represented as a single unit. Collections are introduced to bring a unified common interface to all the objects.
Collection Framework was introduced since JDK 1.2 which is used to represent and manage Collections and it contains:
This framework also defines map interfaces and several classes in addition to Collections.
Advantages:
- High performance
- Reduces developer’s effort
- Unified architecture which has common methods for all objects.