Arithmetic Expressions

1
Arithmetic Expressions

• Addition ()
• Subtraction (-)
• Multiplication ()
• Division (/)
• Integer
• Real Number
• Mod Operator ()

• Same as regular
• Same as regular
• Same as regular
• Depends on the types of the operands involved.
• Remainder operator

2
Order of Operations

• Same as math class
• ()
• , /,
• , -
• Heres an example
• 3 45 - 6/34/8 26 - 432
• 3 20 - 1 12 24
• 10

3
Integer Division

• If the two operands are of type int, then integer
  division occurs
• An integer division truncates (chops off) any
  fractional part of the answer.
• Examples
• 13/4 3
• 7/8 0
• 19/3 6

4
Real Number Division

• If at least one of the two operands is a double
  (or float), then a real number division occurs
• Examples
• 13/4.0 3.25
• 13.0/4.0 3.25
• 19.0/5 3.8

5
Other Issues with Division

• Variable on the left-hand side of an assignment
  is of type int, while the expression on the right
  is a real number
• val 8/5.0, will set val to 1, if val is an int.
• If the variable on the left-hand side is a
  double, but the expression on the right is an
  int, the variable gets set to an int.
• val 8/5, will set val to 1, if val is a double.

6
Mod Operator

• A B returns the remainder when A is divided by
  B, and A and B MUST BE ints!
• Examples
• 125 2
• 196 1
• 147 0
• 19200 19

7
Initializing Variables

• If you declare a variable without a value, then
  that variable initially could equal anything
• Usually, its a good practice to give your
  variables initial values.
• Examples
• int sum 0, value 1
• double price 0.0

8
Defining Constants

• Use define
• Examples
• define FEET_IN_YARD 3
• define PI 3.14159
• Benefits
• Code is Easier to Read
• If a constant needs to be changed, you only
  need to change it at the top of your program.
  (ie. if you find out that some program parameter
  has changed)