CSE 1020: Introduction to Computer Science I

1. CSE 1020: Introduction to Computer Science I Mark Shtern

2. Course Objective • Developing development skills • Writing Java Multiclass application • Introducing the software engineering concern • Study UML, OOP, API

3. Example 01 Write application that calculates rectangle area

4. Example 02 Write application that calculates volume of rectangle couboid

5. Math & Computers • Algebraic laws • (a*b) /c is equal to a * (b/c) • (a + b) – c is equal to a + (b -c)

6. Ex 1.16 • What is program output? char grade= ‘B’; System.out.print(grade); { System.out.print(grade); { grade = ‘C’; System.out.print(grade); } } System.out.println(grade);

7. Ex 1.17 Explain the compile-time error long speed = 1; int size = 7; { boolean even = false; long speed = 5; size = 2; } int even = 3; System.out.println(speed); System.out.println(size); System.out.println(even);

8. Ex 1.17 What is output? long speed = 1; int size = 7; { boolean even = false; size = 2; } int even = 3; System.out.println(speed); System.out.println(size); System.out.println(even);

9. Summary • Types • Declaration • Arithmetic Operations +,-,/,* ,% (remainder) • Casting • Scope

10. Shortcuts a++  a=a+1 a--  a=a-1 a+=6  a=a+6 a*=6 a=a*6

11. Literal • Real • 7D or 7d  7 is double • 2.5E 3  2.5*10^3 or 2500.0 • Boolean • true or false • Character • ‘\t’ , ‘\n’, \’, ‘\\’,’\”’

12. Program Execution Edit Compile Run

13. Java Program Byte code javac Compile-time Errors VM CPU Byte code java instruction

14. Ex 1.18 Is it true that expression a * b * c/d (1) is evaluated as ((a * b) * (c /d)) (2)

15. Ex 1.21 int i = 6; long l = 4; double d = 12; l = i + i; d = i + i; i = l + l; l = d + d; Explain the compile-time error

16. Ex 1.22 int x = 3; int y = 14; double pie = x + y / 100.0; int z = (5 % 4) + 6 / 8; System.out.println (pie); System.out.println(z); Explain the compile-time error or predict its output

17. Math & Computer sqrt(x^2) vs (sqrt(x))^2 (1/x) * x vs x * 1/x

18. Char Type • What is output? char letter = ‘D’; letter = (char) (letter +1); System.out.println(letter); ------------------------------------------ char letter = ‘D’; char letter2 = ‘A’; System.out.println(letter2 - letter);