Programming Articles - Page 2616 of 3366

CPython CPython is the implementation of the language called “Python” in C. Python is an interpreted programming language. Hence, Python programmers need interpreters to convert Python code into machine code. Whereas Cython is a compiled programming language. The Cython programs can be executed directly by the CPU of the underlying computer without using any interpreter. Cython Cython is designed as a C-extension for Python. The developers can use Cython to speed up Python code execution. But they can still write and run Python programs without using Cython. But the programmers have to install both Python and C-compiler as a pre-requisite ... Read More

Compilation − The source code in python is saved as a .py file which is then compiled into a format known as byte code, byte code is then converted to machine code. After the compilation, the code is stored in .pyc files and is regenerated when the source is updated. This process is known as compilation. Linking − Linking is the final phase where all the functions are linked with their definitions as the linker knows where all these functions are implemented. This process is known as linking. image compilation.jpg----- Note − Python programs are both compiled as well as ... Read More

Yes, we can declare the main method as private in Java.It compiles successfully without any errors but at the runtime, it says that the main method is not public.Example:class PrivateMainMethod {    private static void main(String args[]){        System.out.println("Welcome to Tutorials Point");     } }The above code is working successfully at compile time but it will throw an error at the runtime.Output:Error: Main method not found in class PrivateMainMethod, please define the main method as: public static void main(String[] args) or a JavaFX application class must extend javafx.application.Application

Yes, we can execute a java program without a main method by using a static block.  Static block in Java is a group of statements that gets executed only once when the class is loaded into the memory by Java ClassLoader, It is also known as a static initialization block. Static initialization block is going directly into the stack memory. Example class StaticInitializationBlock{    static{       System.out.println("class without a main method");       System.exit(0);    } } In the above example, we can execute a java program without a main method (works until Java 1.6 version). ... Read More

A method which does not have body is known as abstract method. It contains only method signature with a semi colon and, an abstract keyword before it.public abstract myMethod();To use an abstract method, you need to inherit it by extending its class and provide implementation to it.Declaring abstract method staticIf you declare a method in a class abstract to use it, you must override this method in the subclass. But, overriding is not possible with static methods. Therefore, an abstract method cannot be static.If you still, try to declare an abstract method static a compile time error is generated saying ... Read More

A method which does not have body is known as abstract method. It contains only method signature with a semi colon and, an abstract keyword before it.public abstract myMethod();To use an abstract method, you need to inherit it by extending its class and provide implementation to it.A class which contains 0 or more abstract methods is known as abstract class. If it contains at least one abstract method, it must be declared abstract.Instantiating an abstract classOnce a class is abstract it indicates that it may contain incomplete methods hence you cannot create an object of the abstract class.If you try ... Read More

A method which does not have body is known as abstract method. It contains only method signature with a semi colon and, an abstract keyword before it.public abstract myMethod();To use an abstract method, you need to inherit it by extending its class and provide implementation to it.Abstract classA class which contains 0 or more abstract methods is known as abstract class. If it contains at least one abstract method, it must be declared abstract.And yes, you can declare abstract class without defining an abstract method in it. Once you declare a class abstract it indicates that the class is incomplete ... Read More

An exception is an issue (run time error) occurred during the execution of a program. When an exception occurred the program gets terminated abruptly and, the code past the line that generated the exception never gets executed.Multiple exceptions in a codeBefore Java 7 whenever we have a code that may generate more than one exception and if you need to handle the specifically you should use multiple catch blocks on a single try.ExampleThe following Java program contains an array of numbers (which is displayed). from user it accepts two positions from this array and, divides the number in first position ... Read More

A code block/statement in Java to which the control never reaches and never gets executed during the lifetime of the program is known as unreachable block/statement.public class UnreachableCodeExample {    public String greet() {       System.out.println("This is a greet method ");       return "Hello";       System.out.println("This is an unreachable code ");    }    public static void main(String args[]) {       new UnreachableCodeExample().greet();    } }Dead codeA dead code is an unreachable code, but it doesn’t generate compile time error. But if you execute it in eclipse it gives you a warning.ExampleIn ... Read More

A code block/statement in Java to which the control never reaches and never gets executed during the lifetime of the program is known as unreachable block/statement.Generally, it happens whenever a piece of code hasA return statement before it.An infinite loop before it.Java does not support unreachable code. If you have any such statements, (which are unreachable) Java compiler raises a compile time error.Example1In the following Java program, the class UnreachableCodeExample has a method named greet which returns a String value. After the return statement it has a print statement. Live Demopublic class UnreachableCodeExample {    public String greet() {     ... Read More