Karel's Built in Commands

Commands

move();

turnLeft();

turnRight();

turnAround();

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

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

// Can also use "var" to define the "i" (depends on your course)
for (var i = 0; i < COUNT; i++) {
  // Code that will run 'COUNT' times
}

Example of for loops

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

// Or, if your course teaches "var":
for (var i = 0; i < 10; i++) {
	putBall();
}

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

// Or, if your course teaches "var":
for (var i = 0; i < 5; i++) {
	putBall();
	move();
}

Comments

Comments

/* A multi-line comment describes your code
 * to someone who is reading it. */

// Use single line comments to clarify code.