Intro to Git and JavaScript Pairing Lab

The purpose of this lab is to get you and your partner familiar with git, specifically, how to:

• Fork a repository
• git clone down a remote repository
• git add to stage and git commit to commit changes
• git push to push up committed changes from a local repo to a remote repo
• git pull to pull down changes from a remote repo to a local repo
• How to manage merge conflicts

Note: This lab demonstrates a workflow that does not follow best practices as it will likely create many merge conflicts. However, it is a great place to start to learn the foundations of working collaboratively on Git!

Pair Programming

For this lab, you will engage in Paired Programming. This just means you are collaborating live with a programming partner! When pair programming, both partners are always looking at, and working off of the same screen! This creates two roles:

• The driver is the one typing on the computer.
• The navigator is watching and checking their code, make suggestions, and doing research to support the driver.

Each role is important and distinct and individuals may perform differently in each role so it is recommended that you frequently switch between driving and navigating.

Instructions

Read these instructions in their entirety before beginning:

1. You will work in groups to implement various JavaScript functions.
2. One group member, Partner A, will fork this repository. Only one group member should fork the repo. Partner B does not need to fork anything.
3. In the forked repository, Partner A needs to add Partner B as a collaborator. This means that both groups members will have read and write (edit) access to the forked repo. Partner A will share the URL for the repository with Partner B and Partner B should accept the invitation on GitHub (check your email if you don't see a button to do so on GitHub).
4. Both partners should git clone the forked repo to their development/unit-0 directory using SSH.
5. Partner A will drive first with Partner B being the navigator. Partner A will type out the first function while Partner B reviews their code. The navigator may also make suggestions for improvements. Stage, commit, and push the changes up to the main branch of the remote repo (make sure you are in the correct folder in the terminal).
6. Double check the remote repo on Github to ensure the latest commit was successfully pushed up.
7. Then, it will be Partner B's turn to drive and Partner A will be the navigator. Partner B needs to git pull down the latest commit (make sure you are in the correct folder in the terminal). Once the the code for the first function has been pulled down, Partner B will type out the second function, then push their changes up.
8. Continue switching driver-navigator roles for every function, with Partner A typing out all the odd numbered questions and Partner B implementing the even numbers questions. Every time you push up a commit, your partner will need to pull down the changes to their local repo.
9. Your group should be alternating commits like this example below:
10. Once you reach the bonus problems, divide up the questions that you will each be working on. Instead of pair programming and alternating pushing and pulling, you will switch to parallel programming using branches. Read about the Git Branching and PR process and attempt to implement it for this lab! You will need to each create your own branch, submit PRs for your partner to review and merge, and then handle merging branches. You got this!

Troubleshooting Tips

Running into problems? Make sure you have done the following:

0) Did you clone the same repository?

You can check which remote repository you are connected to by running the following command from inside a Git directory:

git remote -v

This will print out the remote repository location that we are using to fetch/pull changes from and push changes to. For example:

origin	https://github.com/benspector-mls/git-js-pairing-lab.git (fetch)
origin	https://github.com/benspector-mls/git-js-pairing-lab.git (push)

Both partners should have the same urls for both fetch and push.

1) Did you stage, commit, and push your code?

You can always use git status to see if you have done these things.

After completing a function, remember to stage, commit, and push your code! The commands might look like this:

git status
git add index.js
git commit -m "completed the fiveToOneHundred function"
git push

2) Did you pull your partner's changes?

Each time your partner pushes a new function to the repository, make sure to use git pull to download those changes!

3) Did you accidentally cause a merge conflict?

If you git push your code before pulling down your partner's code, you will likely cause a merge conflict. No fear — we're prepared for this.

You will likely be presented with three options for how you can configure your repository to handle git pull merging (merge, rebase, fast-forward only).

For now, we recommend using the first option git config pull.rebase false. To avoid running this command EVERY time you first encounter a merge conflict in a repo, run the following commands:

git config --global pull.rebase false
git pull

Then, resolve the conflicts by doing the following:

1. In your code editor, determine which code you want to keep and delete the rest, including the conflict markers.
2. Then, stage, commit, and push your updated files.
3. Finally, make sure that your partner pulls down the new merge commit that you created.

Problems

Be sure to test your functions as you write them! You can invoke the functions after they have been implemented or use console.log to print out their return value.

1. Write a function fiveToOneHundred that console logs all numbers from 5 to 100.

2. Write a function multiplesOfThree that console logs all positive numbers to 100 that is a multiple of 3.

Multiples of 3 are: 3, 6, 9, 12, 15, ...

3. Write a function multiplesOfThreeOrFive that console logs all positive numbers to 100 if that number is either a mulitple of 3 or a mutliple of 5.

3, 5, 6, 9, 10, 12, 15, ...

4. Write a function untilNum that takes in an integer parameter and console logs all numbers from 1 to that number.

untilNum(5)    //prints out numbers 1 through 5
untilNum(9)    //prints out numbers 1 through 9
untilNum(42)   //prints out numbers 1 through 42

5. Write a function multiply that takes in two number parameters and returns their product.

multiply(2, 4)     //returns 8
multiply(10, -5)   //returns -50
multiply(3, 7.5)   //returns 22.5

6. Write a function add that takes in two number parameters and returns their sum. But if the two values are the same, return triple their sum!

add(2, 4)     //returns 6
add(10, -5)   //returns 5
add(3, 7.5)   //returns 10.5
add(5, 5)     //returns 30 because the sum of 5 + 5 = 10 and 30 is triple that
add(6, 6)     //returns 36 because the sum of 6 + 6 = 12 and 36 is triple that

7. Write a function isNegative that takes in a number parameter and returns true is the number is a negative value and false is the number is a positive value.

isNegative(3)         //returns false
isNegative(-2)        //returns true
isNegative(Math.PI)   //returns false

8. Write a function triangleArea that takes in the height and base of a triangle and returns the area of the triangle.

triangleArea(5, 7)    //returns 17.5
triangleArea(6, 8)    //returns 24

9. Write a function betweenTwentyAndFourty that takes in a number parameter and checks whether a given integer is within 20 to 40. It returns true if it is and false if not.

betweenTwentyAndFourty(20)      //return false
betweenTwentyAndFourty(21)     //return true
betweenTwentyAndFourty(39)     //return true
betweenTwentyAndFourty(40)    //return false

10. Write a function largest that takes in three number parameters and returns the largest of the values.

largest(4, 6, 8)        //returns 8
largest(30, 22, 17)     //returns 30
largest(41, 108, 86)    //returns 108

Bonus

Once you reach the bonus problems, divide up the questions that you will each be working on. Instead of pair programming and alternating pushing and pulling, you will switch to parallel programming using branches. Read about the Git Branching and PR process and attempt to implement it for this lab! You will need to each create your own branch, submit PRs for your partner to review and merge, and then handle merging branches. You got this!

11. Write a function printTime that prints out the current time in the format HH:MM:ss. Do not hard code the hour, minute, or seconds values.

12. Write a function isLeapYear to determine whether a given year is a leap year in the Gregorian calendar.

isLeapYear(2000)    //returns true
isLeapYear(1900)    //returns false
isLeapYear(2020)    //returns true
isLeapYear(1999)    //returns false

13. Write a function getExtention to get the extension of a filename.

getExtention("hello.txt")     //returns ".txt"
getExtention("app.js")        //returns ".js"
getExtention("README.md")     //returns ".md"

14. Write a function absoluteNineteen to compute the absolute difference between a specified number and 19. Returns triple their absolute difference if the specified number is greater than 19.

15. Write a function switchLetters that creates a new string from a given string changing the position of first and last characters.

switchLetters("anne")         //return "enna"
switchLetters("hello world")  //return "dello worlh"
switchLetters("a")            //return "a"
switchLetters("")             //return ""

16. Write a function changeString to replace every character in a given string with the character following it in the alphabet/

changeString("abc")             //return "bcd"
changeString("helloworld")      //return "ifmmpxpsme"