Error
Errors:
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Super Karel's Built in Commands
Commands
move(); |
turnLeft(); |
|
turnRight(); |
turnAround(); |
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putBall(); |
takeBall(); |
Methods
Writing a Method
Writing a method is like teaching karel a new word.
Naming Methods: You can name your methods whatever you want, but you can't have spaces in the method name.
Remember that each open bracket { must match with a close bracket }
private void turnRight() { turnLeft(); turnLeft(); turnLeft(); } private void turnAround() { turnLeft(); turnLeft(); } private void yourMethodName() { // Code that will run when you make a call to // this method. }
Conditional Statements
If Statements
Remember that each open bracket { must match with a close bracket }if (condition) { // code that will run if the condition is true }
if (condition) { //code that will run if the condition is true } else { //code that will run if condition is not true }
Example of if statements
if(frontIsClear()) { move(); } if(ballsPresent()) { takeBall(); } else { move(); }
Karel Conditions
Don't forget the()
at the end
frontIsClear() leftIsClear() rightIsClear() facingNorth() facingSouth() facingEast() facingWest() ballsPresent() |
frontIsBlocked() leftIsBlocked() rightIsBlocked() notFacingNorth() notFacingSouth() notFacingEast() notFacingWest() noBallsPresent() |
Loops
Remember that each open bracket { must match with a close bracket }While Loops
while (CONDITION) { // Code that will run while the CONDITION is true. // Once the CONDITION is no longer true, // it will stop. }
Example of while loops
/* This moves Karel to a wall */ while(frontIsClear()) { move(); }
For Loops
for (int i=0; i < COUNT; i++) { // Code that will run 'COUNT' times }
Example of for loops
/* This puts down 10 balls */ for(int i = 0; i < 10; i++) { putBall(); }You can have multiple statements or function calls in a for loop.
/* This puts down five balls and moves after each one */ for(int i = 0; i < 5; i++) { putBall(); move(); }
Use for-loops when you want to repeat something a fixed number of times.
Use while-loops when you want to repeat something as long as a condition is true.
Comments
Comments
/* A multi-line comment describes your code * to someone who is reading it. */ // Use single line comments to clarify code. /** * * A Javadoc comment * is used to describe how a * method or class works. * * It has two *'s on the first line. */
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