Processing: Creative Coding and Computational Art

In the first preceding example, addition and subtraction have the same precedence level,
so the right side of the assignment statement is evaluated from left to right. (The assignment
itself still occurs from right to left.)
The second example combines multiplication, division, and subtraction. Multiplication and
division operations occur before subtraction. Since multiplication and division are at the
same precedence level, this expression is evaluated left to right.
The last example uses the same operands and operators as the second example, but uses
parentheses to group. Since parentheses have the highest precedence, the subtraction in
the parentheses happens first, and then the multiplication/division occurs from left to right.
I’ve covered all the arithmetic operators but one: %, called the modulus operator. When I
first learned about this operator, I found it confusing and a little scary looking and sounding.
It’s actually not such a big deal. The modulus operator doesn’t mean percent, but
rather returns the remainder of the division between two operands. The remainder is the
part left over after the division.
For example, 7 % 2 would evaluate to 1, since 2 goes into 7 three times, leaving a remainder
of 1. Here are some more examples:
17 % 9 evaluates to 8.
6 % 3 evaluates to 0.
23.4567 % 5 evaluates to 3.4567.
In addition to the five arithmetic operators you just looked at, there are quite a few others.
However, you only need to concern yourself with the most common ones for now.
These operators can be broken down into three categories: the equality and relational
operators, the conditional (also sometimes referred to as logical) operators, and the
assignment operators.
Relational operators
The relational operators are very important, and you will use them often. Most of these
operators should look familiar to you from grade school (although probably not the last two):
> (greater than)
>= (greater than or equal to)
< (less than)