CPP01 - Introduction to C++

CPP01 - Introduction to C++

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  Software Development Michael Heron
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  Introduction • Welcome tothe module! • I hope you enjoy it. • In this module we are going to be talking about how to build programs using the C++ programming language. • This serves as preparatory work for you moving onto more advanced coding next semester. • Programming is a lot of fun (honest), but it’s also a difficult topic to learn. • It’s really important that you stick with it!
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  Introduction • Programming isabout more than just learning some technical skills. • There’s a state of mind that goes with it as well. • Part of the fun of programming lies in looking at it like a kind of logical puzzle. • It’s on this basis that many people code recreationally. • Mostly, programming is about pattern recognition. • This is an extremely transferable skill.
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  Structure of theModule • There are three lectures for this module every week: TIMES • There is also a two hour lab every week. TIMES
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  Structure of theModule • In the first two lectures, we’ll talk about programming topics. • In the third, we’ll do some collaborative class-work . • Programming is often best done away from a computer. • In the lab, we’ll alternate between courseworks and class exercises.
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  Structure of theModule • The module has three sets of assignments. • The first is a portfolio of projects developed through the weeks. • Four small programs. • This counts for 20% of your grade. • The second is a larger project that you decide upon yourself. • With guidance/approval from me • This counts for 20% of your grade • The third part is an exam. • This counts for 60% of your grade
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  Programming • Programming isone of the most unique things anyone ever learns to do. • I have never encountered anything quite like programming in terms of the blend of skills it requires. • Fundamentally, it is about compensating for one simple fact. • Computers are soul-crushingly stupid, and they need people to tell them what to do.
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  Class Exercise • So,let’s see what writing a program works like in the abstract. • Get into groups of two or three. • Decide on a simple(ish) shape to draw. • Not a simple geometric shape, but nothing especially complicated. • Then, write out the instructions for drawing that shape as precisely as you can. • For someone who doesn’t know what your shape is supposed to be. • After a few minutes, I’ll draw your shapes on the board from the instructions you give me.
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  A Computer Program •A computer program breaks down into a series of very small, very specific instructions to the computer. • These have to be in the computer’s own language. • A series of low level, primitive grunts and whistles. • 1s, 0s, and the ability to perform trivial operations on those numbers. • In the Olden Days, this is how people wrote computer code. • In machine code
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  Modern Programming • Overthe years, we have increasingly abstracted away from this idea. • We now use what are known as high level languages. • High level indicates how far we are abstracted from the underlying 1s and 0s • Most programming languages are now designed to be human readable. • Well…
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  Modern Programming • C++is an example of a high level language. • It frees us up to think about programs in terms of the flow of logic rather than on the ‘administrative’ work. • We write in a vaguely human readable language. • Special software tools then turn this human readable language into something the computer can understand.
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  Compilation • The processof turning our human readable code into something the computer understands is called compilation. • It’s kind of a translation process. • In order for compilation to be possible, programming languages have to be very strict. • Computers cannot deal with ambiguity. • The exact rules we must obey when giving instructions to the computer is known as the language syntax.
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  Compilation • Where thereis ambiguity, or when things have not been expressed precisely enough for the compiler, it issues what are called syntax errors. • Essentially the compiler says ‘Woah, I don’t even know how to turn that into something the computer understands!’ • These must be fixed before a program can be compiled at all. • C++ complicates it by making the error messages horribly unhelpful, but we’ll talk about these as we go along.
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  The Implications • Theimplications of all of this is that it’s really important to follow instructions that you are given – not just to the letter, but down to the punctuation • Punctuation symbols in computer languages are used to express special meaning. • This will come easier with practice. • The rules aren’t complicated, they are just necessarily fiddly.
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  After Compilation • Onceyour program has no more syntax errors (in technical terms, it compiles), the program is then executed (or run). • Here is where the next level of problems occur. • When a program loads, but doesn’t do what it’s supposed to do, it is said to have logic errors. • The problem is in what code has been written, not how the code has been written.
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  A Note ofAdvice • Please do not look on errors as a bad thing. • They’re really, really not at this stage. • You will learn more from getting errors and fixing them than you will from getting everything right the first time. • Nobody gets everything right the first time. • It’s easy to get discouraged, but you have to think of each error you solve as a little mini-lesson in programming. • As long as you know why it happened, and how to avoid it happening in the future, you just became a better programmer.
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  Writing a C++Program • In the labs, we are going to be using a piece of software called Visual Studio .NET. • It’s tremendously powerful, and as such not the easiest thing in the world to use. • This is a package of software known as an Integrated Development Environment (IDE). • You use your IDE to create the programs that the computer will run.
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  What We Study •This module is not just about writing programs. • You can feel free to disbelieve that, since we’ll be doing that a lot. • It’s about building the skills and mindset needed to be able to write programs properly. • It’s about: • Designing • Coding • Debugging • Testing • Documentation
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  What We Study •You are not going to learn how to do any of this in these lectures. • All these lectures can do is point you in the right direction. • The only way you learn about programming is by practicing it. • It’s an active, doing skill. It’s not something you know, it’s something you do.
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  Practice • The lectureswill introduce new syntax, new tools, and new techniques. • The assessments will make sure you can use them. • In between those two, you have to practice. • Just write programs. Play about with programs you are given. • Experiment with your programs. • Make a copy of code that works, and then just change things around to see what happens. • ‘Well, do that and see what happens’ is something you’ll hear me say a lot.
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  Learning to Program •Programming is a skill built cumulatively. • If you fall behind, you’ll need to make the effort to catch up. • You can’t miss any of the material and still progress. • If you are having problems, the absolutely wrong way to deal with them is to skip classes. • That just makes the problem worse. • Even if you find it difficult to begin with, there’s no reason to believe you always will. • There’s a point, and it’s a different point for everyone, where it all just clicks.
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  Programming is Fun •It really is, and that doesn’t get said enough. • Writing a program is like solving a crossword, or a Sudoku puzzle. • Because it’s a pattern solving exercise, there are also many ways in which you can get better at programming. • Many programmers are also good chess players for example, because both are creative ,pattern solving exercises.
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  Summary • Welcome toyour module! • Programming is challenging, but very rewarding. • It’s also a skill very few people have. • We’ll be writing C++ programs. • We write them • We debug them • We execute them • Most of this is down to you. • I’m here to help, but I can’t really teach you how to do any of this!