Lab 6 - JavaScript Basics

In this lab, you’ll be creating several programs:

1. say twice
2. shout
3. temperature
4. miles
5. * …and a couple of challenging ones: numbers and tree

Summary of Commands:

THESE ARE NOT LAB INSTRUCTIONS.

The following is just a reference. The lab instructions are below.

# create a local repository
git init

# configure it with your name and email
git config user.name  "your name"
git config user.email "your@email.address"

# create a remote repository
curl -u 'your github user name' https://api.github.com/user/repos -d '{"name":"your repository name"}'

# link the two
git remote add origin "your username"@"the url to your repository on github"

# two ways to show all remote repositories
git remote -v
cat .git/config

# removing a remote repository by name (usually origin)
git remote remove name_of_remote

# changing / setting the url of a named remote repository (usually origin)
git remote set-url name_of_remote new_remote_url

# look at the differences between your last save and your current changes (line by line)
git diff --color

# check on the status of your changes
git status

# "stage" or mark your changes as ready to be saved
git add --all

# save!
git commit -m 'my message'

# show a log of your changes so far
git log --color (show your changes so far)

# send to a remote repository (to submit an assignment)
git push origin master 

Instructions

Note that ALL OF THESE FILES MUST BE CREATED IN THE REPOSITORY THAT YOU CREATED FOR THIS LAB.

say twice

Write a program that takes user input and repeats the user input twice (both words on the same lin) in the JavaScript console.

• using SublimeText, create a new file called saytwice.html in your repository directory: ~/Desktop/bzuckerman/lab-06-javascript-conditionals/
• setup an html file, and add script tags… start writing your JavaScript between the script tags
• the program should ask for a word: “Give me a word to say twice”
• the program should repeat the input twice on the same line with a space inbetween… back to the JavaScript console
  • for example, if someone enters “hello” in the prompt dialog
  • the output in the console would be “hello hello”
• example interaction is below (everything after the greater than sign (> is user input using the prompt function):

(prompt) Give me a word to say twice
> hello
hello hello

• save your file in SublimeText
• use status, add commit and push to save your file in version control and submit it

shout

Write a program that takes user input and repeats the user input, but with three exclamation points afterwards.

• using SublimeText, create a new file called shout.html in your repository directory: ~/Desktop/bzuckerman/lab-06-javascript-conditionals/
• setup an html file, and add script tags… start writing your JavaScript between the script tags
• the program should ask for a word: “Give me a word, and I’ll shout it out”
• the program should repeat the word, but with three exclamation points added to it
• the output should go to the JavaScript console
• example interaction is below (everything after the greater than sign (> is user input using the prompt function):

(prompt) Give me a word, and I'll shout it out
> yeah
yeah!!!

• save your file in SublimeText
• use status, add commit and push to save your file in version control and submit it

temperature

Write a program that calculates celsius to fahrenheit based on user input.

• using SublimeText, create a new file called temperature.html in your repository directory: ~/Desktop/bzuckerman/lab-06-javascript-conditionals/
• setup an html file, and add script tags… start writing your JavaScript between the script tags
• the program should ask for the temperature in celsius
• find the formula for celsius to faahrenheit conversion online!
• translate that formula into javascript
• the program should output to the JavaScript console: c degrees celsius is f degrees fahrenheit
• (obvs with f and c substituted with the appropriate calculated values)
• example interaction is below (everything after the greater than sign (> is user input using the prompt function):

(prompt) Please enter a temperature in celsius
> 37
37 degrees celsius is 98 degrees fahrenheit

• save your file in SublimeText
• use status, add commit and push to save your file in version control and submit it

miles

Write a program that calculates miles-per-gallon based on user input for miles driven and gallons of gas used.

• using SublimeText, create a new file called miles.html in your repository directory: ~/Desktop/bzuckerman/lab-06-javascript-conditionals/
• setup an html file, and add script tags… start writing your JavaScript between the script tags
• miles-per-gallon (mpg) can be calculated using the following formula…
• mpg = miles driven / gallons of gas used
• ask the user for the number of miles driven and the gallons of gas used
• calculate miles-per-gallon and output the result to the JavaScript console
• example interaction is below (everything after the greater than sign (> is user input using the prompt function):

(prompt) How many miles did you drive?
>20
(prompt) How many gallons of gas did you use?
>2
Your car gets 10.0 miles per gallon.

• save your file in SublimeText
• use status, add commit and push to save your file in version control and submit it

*numbers

(This one’s hard!) Write a program that outputs the number in the thousands, hundreds, tens and ones places of a number.

• using SublimeText, create a new file called numbers.html in your repository directory: ~/Desktop/bzuckerman/lab-06-javascript-conditionals/
• setup an html file, and add script tags… start writing your JavaScript between the script tags
• ask the user for a number
• calculate the numbers in the thousands, hundreds, tens and ones places
• output each place to the JavaScript console
• one solution is to use some numeric operators to determine each place (maybe modulo, division and subtraction would help)
• you may have to calculate each place separately
• don’t worry about input that’s not a positive whole number below 10,000
• example interaction is below (everything after the greater than sign (> is user input using the prompt function):

(prompt) Please enter a number
> 256

0 thousands
2 hundreds
5 tens
6 ones

• save your file in SublimeText
• use status, add commit and push to save your file in version control and submit it

*tree

(This one’s slightly hard… try doing it in just one line!) Print out a tree!

• using SublimeText, create a new file called tree.html in your repository directory: ~/Desktop/bzuckerman/lab-06-javascript-conditionals/
• setup an html file, and add script tags… start writing your JavaScript between the script tags
• print out an ascii art tree to the JavaScript console

   /\
  /  \
  /  \
 /____\
   ||

• save your file in SublimeText
• use status, add commit and push to save your file in version control and submit it