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

Order of Operations

• Same as math class– () – *, /, % – +, -

• Here’s an example:– 3 + 4*5 - 6/3*4/8 + 2*6 - 4*3*2– 3 + 20 - 1 + 12 – 24– 10

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

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

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.

Mod Operator

• A % B returns the remainder when A is divided by B, and A and B MUST BE ints!

• Examples– 12%5 = 2– 19%6 = 1– 14%7 = 0– 19%200 = 19

Initializing Variables

• If you declare a variable without a value, then that variable initially could equal anything

• Usually, it’s a good practice to give your variables initial values.

• Examples– int sum = 0, value = 1;– double price = 0.0;

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)