CSCI S-1 Section 3

1. CSCI S-1Section 3

2. Deadlines for Homework 2 • Problems 1-8 in Parts C and D • Friday, July 3, 17:00 EST • Parts E and F • Tuesday, July 7, 17:00 EST

3. Connecting to your FAS account (nice.fas.harvard.edu) • Mac OS: Terminal • http://isites.harvard.edu/fs/docs/icb.topic576155.files/terminal.pdf • Windows: SecureCRT • http://isites.harvard.edu/fs/docs/icb.topic576155.files/securecrt.pdf • Downloads site • http://www.fas-it/fas.harvard.edu/

4. Getting around in Linuxhttp://isites.harvard.edu/fs/docs/icb.topic576155.files/UNIX_commands_reference_card.pdf • Listing files • Changing directories • Making directories • Removing directories • Removing files • Copying files • Moving files • Print file to monitor • Your present working directory • ls • cd • mkdir • rmdir • rm • cp • mv • cat • pwd

5. Using Nano • To edit a textfile • nano filename • Inside nano • control+O to save • control+X to exit • additional commands explained in the help at the bottom of the screen.

6. Submitting Homework • Setup your account by running ~libs1/pub/bin/s1setup • Execute the logout command by typing logout and then enter • Login again and make a directory to hold all of your homework • mkdir s1 • Get into s1 • cd s1 • Make a directory for parts C, D (ps21) and E, F (ps22) • mkdir ps21 • mkdir ps22 • Test-drive the submit tool by submitting a temporary part 1 • s1submit ps21 • NB: Your last submission is the one timestamped and graded.

7. Java Exercises Type up this simple program in nano and save it as section3.java class section3 { public static void main(String [] args) { System.out.println("Hello!"); } } Compile it: javac section3.java Run it: java section3

8. Java Exercises Write a java program that will print the following H E L L O \ \ _ " ." JAVA Programming class section3a { public static void main(String [] args) { System.out.println("H E L L O\\\\_ \" .\""); System.out.println("JAVA"); System.out.println("Programming"); } }

9. Java Exercises Rewrite the program using one method to print each line class section3b { static void firstLine() { System.out.println("H E L L O\\\\_ \" .\""); } static void secondLine() { System.out.println("JAVA"); } … public static void main(String [] args) { firstLine(); secondLine(); thirdLine(); } }

10. Understanding Variable Scope class section3c { static int x, y, z; static void first() { int x, y; x = 0; y = 1; System.out.println("x = " + x + " , y = " + y + " z = " + z); } static void second() { int z; y = 7; z = 1; System.out.println("x = " + x + " , y = " + y + " z = " + z); } static void third() { int y; x = 7; y = 1; System.out.println("x = " + x + " , y = " + y + " z = " + z); } public static void main(String [] args) { x = 2; y = 2; z = 3; first(); second(); third(); } }

11. Understanding Variable Scope (cont) class section3c { … public static void main(String [] args) { x = 2; y = 2; z = 3; System.out.println("x = " + x + " , y = " + y + " z = " + z); first(); second(); third(); System.out.println("x = " + x + " , y = " + y + " z = " + z); } } x = 2 , y = 2 z = 3 x = 0 , y = 1 z = 3 x = 2 , y = 7 z = 1 x = 7 , y = 1 z = 3 x = 7 , y = 7 z = 3