Referenced from lesson Player Animation

Directions: The player moves up and down by 20 pixels each time. Write a function called update-player, which takes in the player’s y-coordinate and the name of the key pressed ("up" or "down"), and returns the new y-coordinate.

Contract and Purpose Statement

Every contract has three parts…​

; _____________:______________->______

; _______________________________________________________________________


Write some examples, then circle and label what changes…​

(EXAMPLE (_____________ _________)___________)

(EXAMPLE (_____________ _________)___________)

(EXAMPLE (_____________ ___________)___________)

(EXAMPLE (_____________ ___________)___________)


Write the definition, giving variable names to all your input values…​

(define (_____________ ______)


_____[___________________ _________]

_____[_____________________ _________]

_____[____ __]


These materials were developed partly through support of the National Science Foundation, (awards 1042210, 1535276, 1648684, and 1738598). CCbadge Bootstrap:Algebra by the Bootstrap Community is licensed under a Creative Commons 4.0 Unported License. This license does not grant permission to run training or professional development. Offering training or professional development with materials substantially derived from Bootstrap must be approved in writing by a Bootstrap Director. Permissions beyond the scope of this license, such as to run training, may be available by contacting