Karel's Built in Commands

move();

turnLeft();

putBall();

takeBall();

UltraKarel commands

paint(color);

UltraKarel conditions

randomChance();

colorIs(color);

// Paints a square red.
paint(Color.red);

Colors:

Color.red
Color.blue
Color.green
Color.yellow
Color.cyan
Color.orange
Color.white
Color.black
Color.gray
Color.purple

// Special Random color function
Color.random()

// Paint a square a random color
paint(Color.random());

// Determine if a square is a certain color
if(colorIs(Color.red)){
	move();
}

// Create a color from RGB to paint this square
// paint(Color.createFromRGB(redValue, greenValue, blueValue));
paint(Color.createFromRGB(12, 14, 19));


Random

// Returns true 50% of the time
randomChance()

// Returns true probability percentage of the time
randomChance(probability)

// Returns true 20% of the time.
randomChance(0.2)


// Example
if (randomChance(0.8)) {
	putBall();
}

Functions

Writing a function is like teaching karel a new word.

Naming Functions: You can name your functions whatever you want, but you can't have spaces in the function name.

Remember that each open bracket { must match with a close bracket }

function turnRight() {
	turnLeft();
	turnLeft();
	turnLeft();
}

function turnAround() {
	turnLeft();
	turnLeft();
}

function yourFunctionName() {
  // Code that will run when you make a call to
  // this function.
}

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 (var i = 0; i < COUNT; i++) {
  // Code that will run 'COUNT' times
}

Example of for loops

/* This puts down 10 balls */
for (var i = 0; i < 10; i++) {
	putBall();
}

/* This puts down five balls and
   moves after each one */
for (var 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.

Slides and Notes

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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.