[JAVA][Beginning Java 8 Games Development]

Chapter 3 ■ A Java 8 Primer: An Introduction to Java 8 Concepts and Principles
Java Arithmetic Operators
The Java arithmetic operators are the most commonly used in programming, especially in arcade type games, in
which things are moving on the screen by a discrete number of pixels. Many more complex equations can be created
using these basic arithmetic operators, as you have already learned in math class, from primary school through college.
The only arithmetic operators shown in Table 3-2 that you may not be that familiar with are the modulus
operator, which will return the remainder (what is left over) after a divide operation is completed, and the increment
and decrement operators, which add or subtract 1, respectively, from a value. These are used to implement your
counter logic. Counters (using increment and decrement operators) were originally used for loops, (which I will be
covering in the next section); however, these increment and decrement operators are also extremely useful for game
programming (point scoring, life span loss, game piece movement, and similar progressions).
Table 3-2. Java Arithmetic Operators, Their Operation Type, and a Description of the Arithmetic Operation
Operator Operation Description
Plus + Addition Adds the operands on either side of the operator
Minus – Subtraction Subtracts the right-hand operand from the left-hand operand
Multiply * Multiplication Multiplies the operands on either side of the operator
Divide / Division Divides the left-hand operand by the right-hand operand
Modulus % Remainder Divides the left-hand operand by the right hand-operand, returning remainder
Increment ++ Add 1 Increases the value of the operand by 1
Decrement -- Subtract 1 Decreases the value of the operand by 1
To implement the arithmetic operators, place the data field (variable) that you want to receive the results of the
arithmetic operation on the left side of the equals assignment operator and the variables that you want to perform
arithmetic operations on the right side of the equals sign. Here is an example of adding an x and a y variable and
assigning the result to a z variable:
Z = X + Y;
// Using an Addition Operator
If you want to subtract y from x, you use a minus sign rather than a plus sign; if you want to multiply the x and y
values, you use an asterisk rather than a plus sign; and if you want to divide x by y, you use a forward slash instead of
a plus sign. Here is how those operations look:
Z = X - Y; // Subtraction Operator
Z = X * Y; // Multiplication Operator
Z = X / Y; // Division Operator
You will be using these arithmetic operators quite a bit, so you will get some great practice with these before you
are finished with this book! Let’s take a closer look at relational operators next, as sometimes you will want to compare
values rather than calculate them.
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