eerui

ITT:
We write different ways to produce 'hello world' in the shell
language : c++
no syntax errors, and no copying others work. I'll start with something simple

#include <iostream>

using namespace std;

int main()
{
    cout << "Hello world!" << endl;
    return 0;
}

In Java, the idea of a namespace is embodied in Java packages. All code belongs to a package, although that package need not be explicitly named. Code from other packages is accessed by prefixing the package name before the appropriate identifier, for example class String in package java.lang can be referred to as java.lang.String (this is known as the fully qualified class name). Like C++, Java offers a construct that makes it unnecessary to type the package name (import). However, certain features (such as reflection) require the programmer to use the fully qualified name.

Unlike C++, namespaces in Java are not hierarchical as far as the syntax of the language is concerned. However, packages are named in a hierarchical manner. For example, all packages beginning with java are a part of the Java platform—the package java.lang contains classes core to the language, and java.lang.reflect contains core classes specifically relating to reflection.

In Java (as well as Ada, C#, and others), namespaces/packages express semantic categories of code. For example, in C#, namespace System contains code provided by the system (the .NET framework). How specific these categories are and how deep the hierarchies go differ from language to language.

Function and class scopes can be viewed as implicit namespaces that are inextricably linked with visibility, accessibility, and object lifetime.