Hello Processing - Vula

An Introduction To Programming With Processing
println(5+3);
Consists of two parts, first the function println() which accepts a parameter. In
this case the second part of the statement, the parameter, is an expression and the
expression is 5+3 which evaluates to 8.
One of the basic features of Processing is it's ability to act as a calculator when
computing values separated by mathematical operators such as + (plus), - (minus),
* (multiply), / (divide) and % (modulus). But this inherent ability of Processing
extends a lot further than simply evaluating numerical expressions, as expressions
amongst other types of data can also consist of other typographic characters that
can be evaluated. For example the statement:
println(“h” + “i”);
This statement evaluates to “hi”. Using a mathematical operator in this way is
known as operator overloading and is an inherent quality of Processing that
comes from it being a C based programming language. Operator overloading is a
common feature in higher level languages and simply refers to the level of
abstraction built into a higher or mid level programming language that allows us
to use the same operator in more ways than one. For example the plus sign can be
used to add numbers or other typographic characters, but not numbers and
characters at the same time without the use of a process known as typecasting
(which we will cover in more detail later).
What makes operator overloading so useful is that we often don't need to be
aware of it, because the way that the operator is used will be determined by the
context in which the programmer has used it and this is something that the
program converting our human readable code into a version that is more machine
readable will handle for us.
An example of operator overloading and typecasting in Processing's PDE
An Analysis of a Computer Program 24