Arithmetic Expressions Addition Subtraction Multiplication Division Integer Real

Arithmetic Expressions • • Addition (+) Subtraction (-) Multiplication (*) Division (/) – Integer – Real Number • Mod Operator (%) • • 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)