8.CT.a.1 - Super Mario

What is the difference between a constant and a variable

• A variable can change, a constant stays the same

• A constant can change, a variable stays the same

• There are no differences

• A constant constantly updates, a variable varies its updates

Answer explanation

In modern javascript a constant is declared like so:

const SPEED = 5;

Whereas a variable is declared like so:

var speed = 5;

A constant cannot be changed, but a variable can. In our older version of javascript the "const" declaration doesn't exist yet, so we put a comment before the variable to define them as constants for ourselves.

The GROUND_LEVEL constant defines where sprites in the game world stand on the _-____ .

Answer explanation

The ground level defines the y-coordinate we use to set where sprites cannot fall through

The MAX_JUMP_HEIGHT defines how high a sprite can jump on the _-_________ .

Answer explanation

The max height jump defines the y-coordinate we use to set where sprites cannot jump higher than

How do you declare a variable in Javascript? Select all correct choices

• var intAge = 13;

• var age(5);

• var strName = 'Thomas';

• name = "Thomas";

Answer explanation

Strings (text) can be defined like so:

var name = "Thomas";

Integers (number) can be defined like so:

var age = 5;

SPEED is used to determine mario's sprite object's ...

• .velocityX

• .velocityY

• .velocityX and .velocityY

• the .x and .y coordinates

Answer explanation

In our code, we use SPEED to set the .velocityX and .velocityY of the Mario object. Whether Mario jumps or runs, he's always using the same speed declared by the constant.

Why will this code not run?

• there has to be a number in the variable

• there are supposed to be no spaces in the variable label

• there are no caps in variables

Answer explanation

A variable label must never have a space!

A _______ is a piece of memory that can contain a data value.

createSprite() returns a sprite object

• True

• False

Answer explanation

createSprite() is a GameLab function you can call to create a sprite object. A sprite object has many functions and properties, such as its x and y coordinate or setting its animation.

A parameter is ...

• Extra data passed to the function

• Defines the constraints of the function

• A type of measuring unit like the meter

• A condition to determine how the function will work

Answer explanation

In our example the two parameters are:

createSprite(200, 200)

200, 200

The first sets the x-coordinate.

The second sets the y-coordinate.

This way when the sprite is created it has its position already set.

What does the parameter in setAnimation("bg") do?

• It sets the bg animation from the internet

• The "bg" animation must be the same name as the object

• In the animation tab there is a "bg" animation we set on the sprite object

• Every game has a "bg" animation and you have to call it using this function

Answer explanation

You must upload sprites in the Animation tab and name them accordingly. You can name it anything as long as you know what it's for.

Then you can use the .setAnimation() function of the sprite object to use that animation for the object.