Lecture_02

# Lecture_02 - ENGR 2200U UOIT/FEAS Fall 2007 ENGR 2710U OO...

This preview shows pages 1–6. Sign up to view the full content.

ENGR 2200U UOIT/FEAS Fall 2007 © Mike Eklund ENGR 2710U OO Programming and Design 1 Using Objects Professor Saman Kumarawadu ENGR 2710U Fall 2010 – Saman Kumarawadu ENGR 2710U OO Programming and Design Objectives • To learn about variables • To understand the concepts of classes and objects • To be able to call methods • To realize the difference between objects and object references ENGR 2710U Fall 2010 – Saman Kumarawadu

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
ENGR 2200U UOIT/FEAS Fall 2007 © Mike Eklund ENGR 2710U OO Programming and Design Number Types • Integers: short, int, long 13 • Floating point numbers: float, double 1.3 0.00013 • Numbers are not objects; number types are primitive types ENGR 2710U OO Programming and Design Basic Data Types • Every value has type. • Types boolean either true or false char 16 bit Unicode 1.1 byte 8-bit integer (signed) short 16-bit integer (signed) int 32-bit integer (signed) long 64-bit integer (singed) float 32-bit floating point (IEEE 754-1985) double 64-bit floating point (IEEE 754-1985) String (class for manipulating strings) Java uses Unicode to represent characters internally
ENGR 2200U UOIT/FEAS Fall 2007 © Mike Eklund ENGR 2710U OO Programming and Design Arithmetic Operations • Operators: + - * 10 + n n - 1 10 * n // 10 × n • As in mathematics, the * operator binds more strongly than the + operator x + y * 2 // means the sum of x and y * 2 (x + y) * 2 // multiplies the sum of x and y with 2 ENGR 2710U OO Programming and Design Self Test 1. Which number type would you use for storing the area of a circle? 2. Why is the expression 13.println() an error? 3. Write an expression to compute the average of the values x and y .

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
ENGR 2200U UOIT/FEAS Fall 2007 © Mike Eklund ENGR 2710U OO Programming and Design Answers 1.double 2. An int is not an object, and you cannot call a method on it 3.(x + y) * 0.5 ENGR 2710U OO Programming and Design Types and Variables • Variable is the storage location: has a type, name and a content • Variable declaration examples: String greeting = "Hello, World!"; PrintStream printer = System.out; int luckyNumber = 13; • Variables • Store values • Can be used in place of the objects they store
ENGR 2200U UOIT/FEAS Fall 2007 © Mike Eklund ENGR 2710U OO Programming and Design Declare Variables What type should you use? What name should you give?

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 17

Lecture_02 - ENGR 2200U UOIT/FEAS Fall 2007 ENGR 2710U OO...

This preview shows document pages 1 - 6. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online