Hello World

Introduction

Hello World is a simple program that can be written in almost every programming language as a very first step into that programming language. What is required is documented below:

curiosity about new programming languages
desire to learn
a computer
a text editor
the appropriate compiler for each language

Ada

Ada is a structured, statically typed, imperative, and object-oriented high-level programming language, extended from Pascal and other languages. It has built-in language support for design by contract (DbC), extremely strong typing, explicit concurrency, tasks, synchronous message passing, protected objects, and non-determinism. Ada improves code safety and maintainability by using the compiler to find errors in favor of runtime errors. Ada is an international technical standard, jointly defined by the International Organization for Standardization (ISO), and the International Electrotechnical Commission (IEC). As of 2020, the standard, called Ada 2012 informally, is ISO/IEC 8652:2012.

Ada was originally designed by a team led by French computer scientist Jean Ichbiah of CII Honeywell Bull under contract to the United States Department of Defense (DoD) from 1977 to 1983 to supersede over 450 programming languages used by the DoD at that time. Ada was named after Ada Lovelace (1815–1852), who has been credited as the first computer programmer.

Ada is used to design extremely large software systems. It is often used in US government agencies that depend on no errors in the code. It is currently used in the US Department of Defense, NATO, Airplan Info Management Systems, as well as many railway systems.

Hello World in Ada:


            with Ada.Text_IO; use Ada.Text_IO; 

            procedure hello is 

            begin 

              Put_Line ("Hello World!"); 

            end hello;

BASIC

BASIC (Beginners' All-purpose Symbolic Instruction Code) is a family of general-purpose, high-level programming languages whose design philosophy emphasizes ease of use. The original version was designed by John G. Kemeny and Thomas E. Kurtz and released at Dartmouth College in 1964. They wanted to enable students in fields other than science and mathematics to use computers. At the time, nearly all use of computers required writing custom software, which was something only scientists and mathematicians tended to learn. In addition to the language itself, Kemeny and Kurtz developed the Dartmouth Time Sharing System (DTSS), which allowed multiple users to edit and run BASIC programs at the same time. This general model became very popular on minicomputer systems like the PDP-11 and Data General Nova in the late 1960s and early 1970s. Hewlett-Packard produced an entire computer line for this method of operation, introducing the HP2000 series in the late 1960s and continuing sales into the 1980s. Many early video games trace their history to one of these versions of BASIC. The emergence of early microcomputers in the mid-1970s led to the development of number of BASIC dialects, including Microsoft BASIC in 1975. Due to the tiny main memory available on these machines, often 4 kB, a variety of Tiny BASIC dialects was also created. BASIC was available for almost any system of the era, and naturally became the de facto programming language for the home computer systems that emerged in the late 1970s. These machines almost always had a BASIC interpreter installed by default, often in the machine's firmware or sometimes on a ROM cartridge. BASIC fell from use during the later 1980s as newer machines with far greater capabilities came to market and other programming languages (such as Pascal and C) became tenable. In 1991, Microsoft released Visual Basic, combining a greatly updated version of BASIC with a visual forms builder. This reignited use of the language and "VB" remains a major programming language in the form of VB.NET.

BASIC has no real modern uses other than historic and academic. Many other BASIC dialects have also sprung up since 1990, including the open source QB64 and FreeBASIC, inspired by QBasic, and the Visual Basic-styled RapidQ, Basic For Qt and Gambas. Modern commercial incarnations include PureBasic, PowerBASIC, Xojo, Monkey X and True BASIC (the direct successor to Dartmouth BASIC from a company controlled by Kurtz). Several web-based simple BASIC interpreters also now exist, including Quite BASIC and Microsoft's Small Basic. Many versions of BASIC are also now available for smartphones and tablets via the Apple App Store, or Google Play store for Android. On game consoles, an application for the Nintendo 3DS and Nintendo DSi called Petit Computer allows for programming in a slightly modified version of BASIC with DS button support.

Hello World in BASIC:


            PRINT "Hello, world!"

Pascal

Pascal is an imperative and procedural programming language, designed by Niklaus Wirth as a small, efficient language intended to encourage good programming practices using structured programming and data structuring. It is named in honour of the French mathematician, philosopher and physicist Blaise Pascal.

Based on Wirth's book, Algorithms + Data Structures = Programs, Pascal was developed on the pattern of the ALGOL 60 language. Wirth was involved in the process to improve the language as part of the ALGOL X efforts and proposed a version known as ALGOL W. This was not accepted, and the ALGOL X process bogged down. In 1968, Wirth decided to abandon the ALGOL X process and further improve ALGOL W, releasing this as Pascal in 1970.

On top of ALGOL's scalars and arrays, Pascal enabled defining complex datatypes and building dynamic and recursive data structures such as lists, trees and graphs. Pascal has strong typing on all objects, which means that one type of data cannot be converted or interpreted as another without explicit conversions. Unlike most languages in the C-family, Pascal allows nested procedure definitions to any level of depth, and also allows most kinds of definitions and declarations inside subroutines (procedures and functions). A program is thus syntactically similar to a single procedure or function. Pascal became very successful in the 1970s, notably on the burgeoning minicomputer market. Compilers were also available for many microcomputers as the field emerged in the late 1970s. It was widely used as a teaching language in university-level programming courses in the 1980s, and also used in production settings for writing commercial software during the same period. It was displaced by the C programming language during the late 1980s and early 1990s as UNIX-based systems became popular, and especially with the release of C++.

A derivative known as Object Pascal designed for object-oriented programming was developed in 1985; this was used by Apple Computer and Borland in the late 1980s and later developed into Delphi on the Microsoft Windows platform. Extensions to the Pascal concepts led to the languages Modula-2 and Oberon.

Today Pascal is primarily used to academic purposes, however, a derivative language called Object Pascal continues to be used by Microsoft today for some Windows applications.

Hello World in Pascal:


            program HelloWorld(output); 

            begin 

              Write('Hello, World!') 

            end.

Python

Python is an interpreted, high-level, general-purpose programming language. Created by Guido van Rossum and first released in 1991, Python's design philosophy emphasizes code readability with its notable use of significant whitespace. Its language constructs and object-oriented approach aim to help programmers write clear, logical code for small and large-scale projects.

Python is dynamically typed and garbage-collected. It supports multiple programming paradigms, including structured (particularly, procedural), object-oriented, and functional programming. Python is often described as a "batteries included" language due to its comprehensive standard library. Python was conceived in the late 1980s as a successor to the ABC language. Python 2.0, released in 2000, introduced features like list comprehensions and a garbage collection system capable of collecting reference cycles. Python 3.0, released in 2008, was a major revision of the language that is not completely backward-compatible, and much Python 2 code does not run unmodified on Python 3.

The Python 2 language was officially discontinued in 2020 (first planned for 2015), and "Python 2.7.18 is the last Python 2.7 release and therefore the last Python 2 release." No more security patches or other improvements will be released for it. With Python 2's end-of-life, only Python 3.5.x and later are supported.

Python interpreters are available for many operating systems. A global community of programmers develops and maintains CPython, an open source[34] reference implementation. A non-profit organization, the Python Software Foundation, manages and directs resources for Python and CPython development.

Hello World in Python:


            print('Hello, world!')

x86 Assembly

x86 Assembly Language is a family of backward-compatible assembly languages, which provide some level of compatibility all the way back to the Intel 8008 introduced in April 1972. x86 assembly languages are used to produce object code for the x86 class of processors. Like all assembly languages, it uses short mnemonics to represent the fundamental instructions that the CPU in a computer can understand and follow. Compilers sometimes produce assembly code as an intermediate step when translating a high level program into machine code. Regarded as a programming language, assembly coding is machine-specific and low level. Assembly languages are more typically used for detailed and time critical applications such as small real-time embedded systems or operating system kernels and device drivers.

Each x86 assembly instruction is represented by a mnemonic which, often combined with one or more operands, translates to one or more bytes called an opcode; the NOP instruction translates to 0x90, for instance and the HLT instruction translates to 0xF4. There are potential opcodes with no documented mnemonic which different processors may interpret differently, making a program using them behave inconsistently or even generate an exception on some processors. These opcodes often turn up in code writing competitions as a way to make the code smaller, faster, more elegant or just show off the author's prowess.

Hello World in x86 Assembly:


            ; Image base = 0x00400000 

            %define RVA(x) (x-0x00400000) 

            section .text 

            push dword hello 

            call dword [printf] 

            push byte +0 

            call dword [exit] 

            ret 

            

            section .data 

            hello db "Hello world!" 

            

            section .idata 

            dd RVA(msvcrt_LookupTable) 

            dd -1 

            dd 0 

            dd RVA(msvcrt_string) 

            dd RVA(msvcrt_imports) 

            times 5 dd 0 ; ends the descriptor table 

            

            msvcrt_string dd "msvcrt.dll", 0 

            msvcrt_LookupTable: 

            dd RVA(msvcrt_printf) 

            dd RVA(msvcrt_exit) 

            dd 0 

            

            msvcrt_imports: 

            printf dd RVA(msvcrt_printf) 

            exit dd RVA(msvcrt_exit) 

            dd 0 

            

            msvcrt_printf: 

            dw 1 

            dw "printf", 0 

            msvcrt_exit: 

            dw 2 

            dw "exit", 0 

            dd 0

References

Ada: Ada Wikipedia
BASIC: BASIC Wikipedia
Pascal: Pascal Wikipedia
Python: Python Wikipedia
x86 Assembly: x86 Assembly Wikipedia