Exercises, examples and other material relating to training module C201. This topic is presented on public courses Learning to Program in C, Learning to program in C and C++, Programming in C, C and C++ Programming, Learning to program in C and C++, C and C++ Programming

In C, all code is written in functions and in this module we write the simplest possible C function to display the words "Hello World" on your screen. We also have a first look at the compilers and linkers (also known as loaders) needed with C to convert your code from English-like text into a runnable program.

Articles and tips on this subject		updated
4566	C - why is slow to write and debug) but fast to run? I often say on my courses that you can write code in a morning in Perl, Python or Ruby that would tae a week in C. How come, and why would anyone use C these days? Firstly, C is the underlying language on which others are built. We need it there in the background, even if we don't (ourselves) code ...	2015-11-01
4555	Preprocessor directives in C and C++ - what they mean The C pre-processor runs on your C and C++ code at compile time prior to the main compile process. Source lines starting with the # character are processed to roduce a new source code file (internally - you don't normally see this) which is then the input to the compile process "proper". Preprocessor ...	2015-10-27
4324	Learning to program - variables and constants Further material from our "learning to program in ...." courses ... an introduction to variables and constants variable basics Information - data - needs to be stored in a program between statements. Or rather it needs to be stored in the computer's memory. At the lowest of levels, that's a binary ...	2014-11-22
3917	BODMAS - the order a computer evaluates arithmetic expressions What order does a computer program use to evaluate expressions? If I write   2 + 3 * 4 + 5 does it start off, left to right ...   2 + 3 is 5   5 * 4 is 20   20 + 5 is 25 No! it does not, even though the newcomer might think that was the most natural way for ...	2012-11-10
3591	Integer types, and integer overflows, in C C offers you the ability to define a whole variety of integer types:   short int my_number;   int my_number;   long int my_number; typically occupying 16, 32 and 64 bits of memory (but that is NOT a standard, and you may find different on some systems). And the amount of ...	2012-01-28
3278	Do I need to initialise variables - programming in C, C++, Perl, PHP, Python, Ruby or Java. Starting with a clean slate. Are variables initisialised, and if so, how? Even with this fundamental question, languages vary considerably. C and C++ From my (e)mailbag ... """In a piece of code we’ve written we declare an array, but we do not fill the elements with values, we assume (dangerous ...	2011-05-05
3234	Your program - you just provide the filling in the sandwich You may think (and say) that you're writing a program ... but you never write a complete program these days. What you do is to provide the filling to the sandwich - the bit that changes from one application / requirement to the next, and you then make use of standard surrounding material - the bread. On ...	2011-04-09
3120	Learning to write good programs in C and C++ - separating out repeated code From our "learning to program in C and C++ day" yesterday - that's how we started our working year in the training business in 2011. "Learning to" courses, where we take people through the basic coding principles and concepts and in the language they'll actually be using are both the hardest work to ...	2011-01-08
2842	Staring a C course with Hello World - why? Every programming course starts with a "Hello World" program - that's a program which does no more than print out the words "Hello World" when you run it - truely minimalist. It's not just convention that courses start that way - it's also very sensible as it allows he tutor to teach the delagates ...	2010-07-01
2576	What does const mean? C and C++ If you declare a variable to be a const, you're telling the compiler that it's a read-only variable and that it won't be changed throughout its existance. A values that's passed in as a parameter to a function, for example, will be left alone until the function exits. That does not stop you from deriving ...	2010-01-15
2005	Variables and pointers and references - C and C++ If I have a variable called "weight" that contains a float, I can use and set its value by using that name. Pointers If - in C or in C++ - I declare a variable to be a pointer then that variable may contain a memory address ... I use a * in my type declaration, and then I use & in my assignment: float ...	2009-01-23
1671	Compiling C programs with gcc - an overview Gcc - the "Gnu Compiler Collection" - is used to compile AND to link C language programs in an open source environment. A single command - gcc runs a series of phases that take you from source code through to an executable program file, with the actual steps taken works out based on: • the extensions ...	2008-06-10
888	Turning C from source to a running program With scripting languages (or near-scripting languages) such as shell, Tcl, Perl, Python and PHP, the developer just edits a file of program code, and tests it - the tools that he uses roll the translation of his source into something that can be run without him having to make further inputs. C is somewhat ...	2006-10-06

cond01.c	C and C++ preprocessor examples
first.c	First program and some comments
hello.c	First C program
makefile	makefile for C version of "hello world"
second.c	Commenting code in C
t2.c	What happens when you overflow
tara.c	Sample function to illustrate inclusion