Before we start: Any questions on Karel?

Transcription

1 Control Flow

2 Before we start: Any questions on Karel?

3 Newspaper Karel Any trouble implementing this task?

4 Karel can also repair Karlův!

5 That s fun!...

6 but a robot should get prepared for the dangers of the world

7

8 awareness about the environment would save lives

9 awareness about the environment would save lives Karel should know how to: count the steps

10 awareness about the environment would save lives Karel should know how to : count the steps check what s around

11 awareness about the environment would save lives Karel should know how to : count the steps check what s around adjust to the environment

12 But first: Who likes dancing here?

13 Dancing Karel import stanford.karel.*; public class DancingKarel extends SuperKarel { public void run() { dance(); dance(); dance(); dance(); private void dance() { move(); move(); turnleft(); Doing it once is not a real dance, what about some more loops

14 Dancing Karel import stanford.karel.*; public class DancingKarel extends SuperKarel { public void run() { for(int i=0;i<4;i++) { dance(); private void dance() { move(); move(); turnleft();

15 Dancing Karel import stanford.karel.*; public class DancingKarel extends SuperKarel { public void run() { for(int i=0;i<4;i++) { for(int k=0;k<4;k++) { dance();

16 Don t Know World Size?

17 Work in Any World Before After Before After

18 While Loop

19 While Loop import stanford.karel.*; public class BeeperLine extends SuperKarel { public void run() { // example while loop while(condition) { code to repeat Check the condition True -> execute Check the condition True -> execute. Check the condition False-> don t execute. Continue the rest of the program

20 Place Beeper Line import stanford.karel.*; public class BeeperLine extends SuperKarel { public void run() { // example while loop while(frontisclear()) { move(); // extra put beeper Any guess what this code will do? How should we modify it to have beepers on the line?

21 Place Beeper Line import stanford.karel.*; public class BeeperLine extends SuperKarel { public void run() { // example while loop while(frontisclear()) { move(); // extra put beeper

22 Place Beeper Line import stanford.karel.*; public class BeeperLine extends SuperKarel { public void run() { // example while loop while(frontisclear()) { move(); // extra put beeper

23 Place Beeper Line import stanford.karel.*; public class BeeperLine extends SuperKarel { public void run() { // example while loop while(frontisclear()) { move(); // extra put beeper

24 Place Beeper Line import stanford.karel.*; public class BeeperLine extends SuperKarel { public void run() { // example while loop while(frontisclear()) { move(); // extra put beeper

25 Place Beeper Line import stanford.karel.*; public class BeeperLine extends SuperKarel { public void run() { // example while loop while(frontisclear()) { move(); // extra put beeper

26 Place Beeper Line import stanford.karel.*; public class BeeperLine extends SuperKarel { public void run() { // example while loop while(frontisclear()) { move(); // extra put beeper

27 Place Beeper Line import stanford.karel.*; public class BeeperLine extends SuperKarel { public void run() { // example while loop while(frontisclear()) { move(); // extra put beeper

28 Place Beeper Line import stanford.karel.*; public class BeeperLine extends SuperKarel { public void run() { // example while loop while(frontisclear()) { move(); // extra put beeper

29 Place Beeper Line import stanford.karel.*; public class BeeperLine extends SuperKarel { public void run() { // example while loop while(frontisclear()) { move(); // extra put beeper

30 Place Beeper Line import stanford.karel.*; public class BeeperLine extends SuperKarel { public void run() { // example while loop while(frontisclear()) { move(); // extra put beeper

31 Place Beeper Line import stanford.karel.*; public class BeeperLine extends SuperKarel { public void run() { // example while loop while(frontisclear()) { move(); // extra put beeper

32 Place Beeper Line import stanford.karel.*; public class BeeperLine extends SuperKarel { public void run() { // example while loop while(frontisclear()) { move(); // extra put beeper

33 Place Beeper Line import stanford.karel.*; public class BeeperLine extends SuperKarel { public void run() { // example while loop while(frontisclear()) { move(); // extra put beeper

34 Which Loop Repeat Process Know how many times Don t know how many times For Loop While Loop

35 What if you only want to perform something once based on a condition?

36 If statement

37 import stanford.karel.*; public class IfExample extends SuperKarel { public void run() { If Statement // example of an if statement if(condition) { code to run if condition is true

38 import stanford.karel.*; public class IfExample extends CSBridgeStudent{ public void run() { If Statement // example of an if statement if(youareincsbridge()) { raiseyourhand(); Assume yourself as Karel and execute this program!

39 Let s teach Karel to be more careful and stop killing itself trying to go through walls. Could there be a safer way to move?

40 import stanford.karel.*; public class IfExample extends SuperKarel{ public void run() { safemove(); If Statement private void safemove() { if(frontisclear()) { move();

41 We can also specify what will happen if the condition is false

42 If-else statement

43 Karel goes to the army: - If there is beeper take it - If there is no beeper put one silly? That s the point!

44 import stanford.karel.*; public class IfExample extends SuperKarel{ If / Else Statement public void run() { invertbeeper(); private void invertbeeper() { if(beeperpresent()) { pickbeeper(); else {

45 Karel Conditions

46 Your tasks this afternoon

47 1. Build Karlův Karel

48 2. Mountain Karel Before After

49 2. Mountain Karel Should work on a world of any size J

50 3. Random Painter

51 What if I finish early?

52