Vocabulary

• JavaScript: JavaScript is a text-based programming language that is widely used in web development.
• Comments: Comments use certain symbols to document code and help other people understand what your code does. In JavaScript, single line comments are started with two forward slashes (//).
• "For" loop: "For" loops execute the same code a certain number of times. They are useful when you need to count (e.g., count from 0 to 9) or repeat an action multiple times.
• Syntax: Syntax is the set of rules that govern how a language is structured. JavaScript syntax is a set of rules that define what correctly formatted code looks like, but if you write a line of code in JavaScript with incorrect syntax, your program won’t run!

Objectives

Students will...

• Use JavaScript commands to move an Actor
• Identify patterns in their code
• Use "for" loops to reduce lines of code
• Add descriptions to their code with comments

Activities (35 minutes)

Facilitate as students complete the Introduction to JavaScript modules on their own:
1. Start the Hack (Puzzle)

• Students are introduced to the main Actor, Skyla. Their goal is to move Skyla to the portal using JavaScript commands.
• In this module, students are taught to use the forward command which moves Skyla forward one step each time it is used.
• Remind students to include a semicolon at the end of each command.
• Tell students to click the orange “Play” button on the bottom right of their screen to run their code.

2. Step Up (Puzzle)

• Students are taught how to comment out code in JavaScript using two forward slashes "//".
• This puzzle has too many “forward” commands. Remind students that commenting out code before the command makes the computer skip over that command. Students will need to use the forward slashes to comment out the extra forward commands in the code so that Skyla can get to the portal.
• Tell students that the stairs do not count as a block so one forward command will move Skyla to the next colored block.

3. Turn The Corner (Puzzle)

• Students are introduced to the “turnLeft” command which will turn Skyla to the left.
• Tell students that the “turnLeft” command does NOT move Skyla forward, it will only change the direction she is facing.

4. Staircase (Puzzle)

• Students will need to apply their knowledge of both the “forward” and “turnLeft” command to code Skyla to move up the first staircase, turn left, then move up the second staircase.
• Remind students that Skyla will climb the stairs automatically without any additional forward commands.

5. Zig-Zag (Puzzle)

• This module introduces the “turnRight” command which turns Skyla to the right.
• Tell students that the “turnRight” command does NOT move Skyla forward, it will only change the direction she is facing.
• Students will need to use the “forward,” “turnRight,” and “turnLeft” commands to move Skyla through the sharp corners.

6. Deja Vu (Puzzle)

• This module explains the concept of "for" loops, which are used when there is a pattern in the commands that needs to be repeated a specific number of times.
• Students will need to determine what the pattern is in the puzzle and then write a "for" loop that repeats that pattern until Skyla reaches the portal.
• Give a hint: Tell students that they need to include one forward command inside the “for” loop.
• Note: By convention, people tend to use “0” as the initial value for initializer and use the “<” operation in the end condition.

7. Up and Down (Puzzle)

• Two new commands are added to the list of commands available for students: “longJump” and “highJump.”
• Tell students that the “longJump” command will move Skyla forward over a one block gap while the “highJump” command will move Skyla up to a platform in front of her.
• Are students struggling? Check that they are using each jump command at the correct time.

8. Onwards, Forward! (Puzzle)

• In this module, students will need to combine their knowledge of "for" loops with the new command, “fire.”
• Tell students that the “fire” command launches a laser that will travel up to 5 tiles ahead, so Skyla should use that command when she is close to the enemy.

9. Jump, Forward (Puzzle)

• Encourage students to find a repeatable pattern of commands that can be used inside a "for" loop. They do not need to use a "for" loop to complete this puzzle, but using a loop will eliminate repetitive lines of code.
• Give a hint: Remind students that firing the laser shoots the laser for 5 blocks, so they can fire before they jump.

10. Forward, Jump (Puzzle)

• Encourage students to identify the pattern and create a “for” loop to move Skyla to the portal.