SuperJava Karel's Built in Commands

move();

turnLeft();

turnRight();

turnAround();

putBall();

takeBall();

Methods

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 (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

frontIsClear()
leftIsClear()
rightIsClear()

facingNorth()
facingSouth()
facingEast()
facingWest()

ballsPresent()
            

frontIsBlocked()
leftIsBlocked()
rightIsBlocked()

notFacingNorth()
notFacingSouth()
notFacingEast()
notFacingWest()

noBallsPresent()
            

Loops

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();
}

/* This puts down five balls and
   moves after each one */
for(int i = 0; i < 5; i++)
{
    putBall();
    move();
}

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.
 */

Slides and Notes

No slides available for this video

Collaborate on this sandbox program!

Admin Only. Not visible to customers

A collaborative program is a program you can work on with a partner or group of people. The program shows up in all of your sandbox pages, and when any of you save code, it will save it for each person.

Embed Your Code On an HTML Page

Want to use your CodeHS code outside of CodeHS? Use this embed code to get started.

How to Use

Version 1: On Your Computer

1. Create a file called codehs.html on your desktop
2. Put the html below into the codehs.html file and save it
3. Now double click the file to open it in a web browser

Version 2: Online

1. Create a file called codehs.html on your desktop
2. Put the html below into the codehs.html file and save it
3. Upload this file to the internet
4. Visit your web page

Note this only works on single files currently.