CMSC 150 Introduction TO Computing

1. CMSC 150IntroductionTOComputing CS 150: Wed 11 Jan 2012

2. Quote of the Day “A smartphone today has more computing power than all of NASA did when it put a man on the moon in 1969.” - Paul Otellini, Intel CEO Quoted from Michael J. Miller’s ForwardThinking blog

3. Homework, due Wednesday 1/18 • p. 39 - 40: 2, 3, 7, 9 • p. 127 - 129: 4, 6, 7, 8, 10, 11 • p. 130: #4 and 5 (can be done on pencil and paper or as a BlueJ project - use project name hw1_<your_netid> as your project name, and be sure to put your name in the comment at the top of the .java file if you do this in BlueJ) • Bonus problem: p. 128: #6

4. Compiling & Executing Compiler Java Virtual Machine Java Program (Source) Java Program (Byte Code) Java Program (Byte Code) Java Program (Source) You write the .java source code into a text file using an IDE, e.g., BlueJ

5. Compiling & Executing Compiler Java Virtual Machine Java Program (Source) Java Program (Byte Code) Java Program (Byte Code) Java Program (Source) The compiler is a program that converts source to binary; Included as part of Java

6. Compiling & Executing Compiler Java Virtual Machine Java Program (Source) Java Program (Byte Code) Java Program (Byte Code) Java Program (Source) The .class byte code file (binary) can be executed

7. Compiling & Executing Compiler Java Virtual Machine Java Program (Source) Java Program (Byte Code) Java Program (Byte Code) Java Program (Source) Java VM is a program that executes byte code instructionson the CPU

8. RAM vs. Hard Drive

9. Your Program’s State Your .java source code file is saved to disk

10. Your Program’s State When you compile, the .class binary file is also saved to disk

11. Your Program’s State When you run the program, the Java VM loads the binary version into RAM…

12. Your Program’s State so that the instructions can be executed on the CPU

13. Let’s Move Into BlueJ…