book

Computer Programming for Absolute Beginners

by Joakim Wassberg

July 2020

Beginner

430 pages

9h 3m

English

Packt Publishing

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Why subscribe?ContributorsAbout the authorAbout the reviewerPackt is searching for authors like you
Who this book is for?What this book covers?To get the most out of this bookDownload the example code filesDownload the color imagesConventions usedGet in touchReviews
A brief history of computingA brief history of programmingWhat is a program?How does a computer program work?Understanding the binary systemUnderstanding ASCII and UnicodeRepresenting other forms of dataBoolean algebraMachine code – the native language of the computerExample machine codeSummary
Why do we have programming languages?How programming languages have evolved?The modern era of programming languagesWhy so many languages?The family tree of programming languagesTranslating code into something that the computer understandsInterpretingCompiling Comparing interpretation and compilationLanguages that both compile and interpretSyntax and the building blocks of a programming languageKeywordsOperatorsCode blocksRelations to mathematicsSummary
Standalone applicationsClient-server applicationsExample of a chat applicationExample of an email clientClient-server, a two-part solutionWeb applicationsExample of a social networkWhat makes web applications unique?Mobile applicationsDistributed applicationsSETI@homePeer-to-peer networksCloud-based applicationsAdvantages of adopting cloud-based applicationsCloud service modelsOther types of applicationsSystems softwareProgramming softwareServerless applicationsSummary
Code modulesWorking with software projectsWorking with packages to share codePackage managersAvoiding conflicts using namespacesDelving into namespacesNamespaces in JavaScriptNamespaces in PythonNamespaces in C plus plusNamespaces in other languagesUsing namespaces in our calculator applicationSummary
The importance of sequencesDefining the problemThe solution to the problemUnderstanding statementsCompound statementsSeparating statementsMaking the code readable by indenting and using empty linesMaking the code understandable using commentsSummary
Declaring and initializing variablesUnderstanding variablesPrimitive data typesBoolean typeNumeric typeComposite typeOperators – things we can do with variablesThe concept of values and reference variablesWorking with numbersManipulating stringsSummary

Controlling the execution pathSelection statementsIteration statementsConditional statementsSelection with the if statementSelection with the switch statementIteration with the for loopIteration with the while loopIteration with the do while loopIterating over sequences using for eachSummary
Deciding what goes into a functionWriting a functionMoving code into a functionReturning values from a functionFunction argumentsFunctions in actionSplitting the code furtherPutting it all togetherLocal and global variablesSummary
Understanding software bugsNASA's Mars Climate OrbiterThe Morris wormDefining a software bugUnderstanding types of software bugsArithmetic errorsDivision by zeroArithmetic overflow/underflowLogical errorsSyntax errorsFinding bugs using a debuggerBreakpointsWorking with exceptionsCommon reasons for exceptionsExceptions and the call stackHandling exceptionsSummary
Understanding structured programmingStatementsProgram stateComparing imperative and structured programmingUnderstanding object-orientated programmingClasses and objectsUnderstanding encapsulationClass methodsInheritanceUnderstanding functional programmingPure functionsMutable and immutable dataAvoiding side effectsDeclarative programmingFirst-class functionsUnderstanding logic programmingOther paradigmsFunction-levelArray programmingQuantum programmingMulti-paradigm languagesSummary
Understanding version control systemsUnit testingIntegration testingOther types of testsSoftware releasesUnderstanding software deploymentDeployment automationCode maintenanceSoftware development process methodologiesWaterfall developmentSpiral modelAgile developmentSummary
Defining code qualityCISQ's quality modelUnderstanding user qualityPutting them togetherWriting code with readability in mindUsing comments and documentation wiselyUsing names as documentationReading other people's codeRewriting your codeWriting code with efficiency in mindRemoving redundant or unnecessary codeOptimizing the use of memory and processorsUsing efficient algorithmsIs smart code smart?Code quality – best practicesLimiting line lengthLimiting function/method lengthAvoiding deep nesting Using the DRY principleUsing code conventionsSummary
The pseudocode examplesHello world in pseudocodeVariables declaration in pseudocodeThe for loop in pseudocodeFunctions in pseudocodewhile loops, user input, if, and for loops in pseudocodeC plus plusHello world in C plus plusVariable declaration in C plus plusThe for loop in C plus plusFunctions in C plus pluswhile loops, user input, if statements, and foreach loops in C plus plusC#Hello world in C#Variable declaration in C#The for loop in C#Functions in C#while loops, user input, if statements, and foreach loops in C#JavaHello world in JavaVariable declaration in JavaThe for loop in JavaFunctions in Javawhile loops, user input, if statements, and foreach loops in JavaJavaScriptHello world in JavaScriptVariable declaration in JavaScriptThe for loop in JavaScriptFunctions in JavaScriptwhile loops, user input, if statements, and foreach loops in JavaPHPHello world in PHPVariable declaration in PHPThe for loop in PHPFunctions in PHPwhile loops, user input, if statements, and foreach loops in PHPPythonHello world in PythonDeclaring variables in PythonThe for loop in PythonFunctions in Pythonwhile loops, user input, if statements, and foreach loops in Python
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Content preview from Computer Programming for Absolute Beginners

Chapter 8: Understanding Functions

There are a number of useful concepts that we, as programmers, always should follow. One is to write code that is easy to read and understand. Another is to avoid duplicating code. When you start out your career as a programmer, you will find yourself copying and pasting code and just changing some small things here and there. This is a bad habit as it nullifies the first concept of code that is easy to read because reading more or less the same lines over and over is tedious and it is hard to spot the tiny differences.

A better solution is to package code that we want to reuse several times into a function. A function is a way for us to give a name to a block of code and then, with this name, the code block ...