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What is a programming language?

Programming languagesprogramming languagesProgramming languages differ from languages we use every day in that they are more precise and unambiguous; it can be said that they are more formalised. A programming language comprises an appropriate set of instructions, keywordskeywordskeywords and the rules of syntaxsyntaxsyntax. The syntax of a programming language is a set of rules that the written codecodecode must follow in order to be recognised as a programmeprogrammeprogramme. Syntax includes available symbols, mathematical and logical operators and keywords, which can be used while writing a programme. Keywords usually come from the English language and are used as commands, instructions or declarations, e.g. BEGIN, END, FUNCTION, IF, DO, STOP, CONTINUE, GO, PRINT. Instructions describe operations such as: inserting or displaying data, performing calculations, specifying conditions or the number of iterations. You must be careful when you write a computer programme since it will not run if it has even the slightest error or a missing coma or semicolon.

Some programming languages are created from scratch, however most of them evolve from already known solutions. Many keywordskeywordskeywords and rules of syntaxsyntaxsyntax are the same in various programming languages. Therefore learning one programming language enables mastering another one quicker.

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ilustracja przedstawia rozsypankę wyrazową składającą się z nazw języków programowania. Słowa pisane są różną wielkością czcionek, jedne można z łatwością odczytać, inne są tak małe, że praktycznie niewidoczne. Wymienione języki programowania to: C, C++, Pearl, Algol, Assembly, Pascal, Python, Ruby, Java, JavaScript, Lisp, VP, Prolog.

What is a computer programme?

A computer programmeprogrammeprogramme is an interpretation of a algorithm written in a selected programming language. An algorithm is a step‑by‑step instructioninstructioninstruction on how to solve a problem or perform a task. The examples of algorithms are a recipe for a cake or describing the way from home to the cinema. In computer science, an algorithm is a set of steps to be performed by a computer programme in order to complete a task.

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Ilustracja przedstawia kod programu komputerowego zajmujące całą przestrzeń. Za ciągami liter kryje się twarz dziecka. Na pierwszym planie widoczny napis a computer programme = syntax rules + keywords.

Who wrote the first programme?

Ada Lovelace, the daughter of the poet Lord Byron, wrote the first ever algorithm in 1843. She completed the work of Charles Babbage on an analytical machine with her own description of an algorithm intended to be carried out by such a machine. The algorithm generated the consecutive Bernoulli numbers. Only in 1991, a working specimen of the machine was constructed using materials that would have been available in Lovelace’s days.

There are many classifications of programming languagesprogramming languagesprogramming languages, depending on a specified criterion.

Classification by the method of code processing

1. CompiledcompiledCompiled languages – the source codecodecode is translated into the machine language, which is understandable for the processor – C++, Pascal.

2. InterpretedinterpretedInterpreted languages – the source code is directly translated and executed by a programmeprogrammeprogramme called an interpreter – Perl, JavaScript.

3. Mixed languages – i.e. compiled to bytecode and interpreted by a virtual machine – Java.

Classification by a programming paradigm (pattern)

1. Non‑structurednon‑structuredNon‑structured languages – Basic.

2. Structured languages (programmes are made up of smaller elements, procedures, functions etc.) – Pascal, C.

3. Object‑orientedobject‑orientedObject‑oriented languages (programmes are made up of objects, which have their properties and perform operations) – C++, Java.

Learning one programming language enables mastering another one quicker.

Exercises

Glossary

Keywords

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