C Programming Yellow Book

Simple Data Processing
Manipulating Data
The convention in C# for the kind of variables that we are creating at the moment is to
mix upper and lower case letters so that each word in the identifier starts with a capital:
float averageIceCreamPriceInPence;
This is sometimes called camel case, presumably because of the "humps" in the
identifier which are caused by the capitals.
Programmer’s Point: Think about the names of your variables
Choosing variable names is another skill you should work at. They should be long enough to be expressive but not so
long that your program lines get too complicated. Perhaps the name averageIceCreamPriceInPence is a bit over the
top in this respect. But I could live with it. Remember that you can always do sensible things with your layout to make
the program look OK:
averageIceCreamPriceInPence =
computedTotalPriceInPence / numberOfIceCreams;
2.2.6 Giving Values to Variables
Once we have got ourselves a variable we now need to know how to put something
into it, and get the value out. C# does this by means of an assignment statement. There
are two parts to an assignment, the thing you want to assign and the place you want to
put it, for example consider the following:
class Assignment
{
static void Main ()
{
int first, second, third ;
first = 1 ;
second = 2 ;
third = second + first ;
}
}
Code Sample 02 Silly Assignment Example
The first part of the program should be pretty familiar by now. Within the Main
function we have declared three variables, first, second and third. These are each
of integer type.
The last three statements are the ones which actually do the work. These are
assignment statements. An assignment gives a value to a specified variable, which
must be of a sensible type (note that you must be sensible about this because the
compiler, as we already know, does not know or care what you are doing). The value
which is assigned is an expression. The equals in the middle is there mainly to confuse
us, it does not mean equals in the numeric sense; I like to think of it as a gozzinta (see
above). Gozzintas take the result on the right hand side of the assignment and drop it
into the box on the left, which means that:
2 = second + 1;
- is a piece of programming naughtiness which would cause all manner of nasty errors
to appear.
Expressions
An expression is something which can be evaluated to produce a result. We can then
use the result as we like in our program. Expressions can be as simple as a single value
and as complex as a large calculation. They are made up of two things, operators and
operands.
C# Programming © Rob Miles 2015 28