Javascript Ninja: Mastering the Basics

Exercise Objectives

• Gain practice coding proper syntax for Javascript data types
• Gain experience with Git: add and commit your code frequently.
• Feel comfortable searching through and using MDN's Documentation.
• Access and change values for Javascript data types (String, Array, Objects)

Setup

• In today's homework folder, touch a script.js file.
• Open the file by typing atom script.js in terminal.
• You will write your Javascript in here. You can run and test your code in the terminal by running node script.js.

Instructions

• Get through all the challenges and be crowned Javascript Ninja Warrior.
• You can comment out code you're not using with the shortcut cmd + /.
• Each instruction's code should go on its own line.
• You need to test your variables, even if there is no instruction to console log them. Make sure you're logging the right value by leaving all other console logs commented out to avoid mega confusion down the road.

SYNTAX MATTERS!

• Half the struggle with programming is dealing with syntax errors. Since coding is about writing a specific set of instructions, it's important to pay extra attention to your code: capitalization, lower case, correct symbols, quotes, semi-colons, etc... it matters. If you're not seeing the answer as you expect or you get a syntax error.. double check your syntax, character by character.

Challenge 1: Booleans

1. Create a variable a and set it equal to true.
2. Create a variable b and set it equal to false.
3. Write a statement using a and b that evaluates to false.

• console log the result to terminal

4. Write a statement using a and b that evaluates to true.

• console log the result to terminal

For each expression below, indicate whether it is 'truthy' or 'falsey' by assigning a variable a value of either true or false:

5. true && false
6. true && 1 != 1
7. "1" === 1
8. !(true && false)
9. false || 0 != 0
10. 3 >= 3 && (!("banana" === "banana" || "javascript" === "fun"))
11. null === undefined
12. isNaN(undefined)
13. 🎯 Commit -m "Commit 1: Boolean Skills"

Challenge 2: Numbers

Refer to the MDN Docs about Math.

1. Create a variable d and set it equal to a 10.
2. Create a variable e and set it equal to 13.445.
3. Console log the difference.
4. In the next line, set e equal to Infinity.
5. Console log the difference.
6. Using Math.min, create a variable called minNumber and set it equal to the smaller value between d and e.
7. Using Math, create a variable called superPower, set it equal to 9000 to the power of one-half.
8. Using Math, create a variable called randomNum and set it equal to a random number rounded down between 1 and 10.
9. Console log the result of randomNum and make sure there are no decimals.
10. 🎯 Commit -m "Commit 2: Number Skills"

Challenge 3: Strings

Refer to the String methods listed in MDN Docs

1. Create a variable called myName and set it equal to your first name.
2. Create a variable called myFavoriteThing and set it equal to "long walks on the beach."
3. Create a variable called myQuote. Using string interpolation, use myName and myFavoriteThing to output "Hi, my name is Christine and I like long walks on the beach." Except it should say your name, not Christine. Mind the spacing!
4. Using a different string interpolation method (string literals?), console log the exact same output.
5. Create a variable called number and set it equal to 10.
6. Create a variable called doesItWork and set it equal to myName + number. Console log it. Is it what you expected?
7. Create a variable called thirdCharacter and set it equal to the third character in myName. Console logging thirdCharacter should give you back only the 3rd letter in your name.
8. Create a variable called secondWord. Using slice on myFavoriteThing, set secondWord equal to the string "walks" (no spaces).

• var secondWord = "walks" does not count.

9. 🎯 Commit -m "Commit 3: String Skills"

Challenge 4: Arrays

1. Create a variable coolArray and set it equal to an empty array.
2. Set the variable coolArray to an array with 3 Strings and 3 Numbers.
3. Console log the last element of the array.
4. Set the second value of coolArray to the string "Nunchuck Skills".
5. Set the third value of coolArray to the Number 100.
6. Push the Boolean value true into coolArray.
7. Console log the data type of the third element of the array.
8. Console log coolArray. Does it reflect all the above changes?
9. 🎯 Commit -m "Commit 4: Array Skills"

Challenge 5: Objects

Add the following object to script.js and write code to access/change the properties for the heart object:

var heart = {
  bpm : 140,
  increaseBpm : function(value) {
    this.bpm += value;
  }
}

1. Create a variable called bpm and set it equal to heart's bpm value.

• var bpm = 140 does NOT count! Access 140 some how.

2. Set heart's bpm to 120.
3. Write a new function within the heart object that will decrease bpm by a value of the user's choosing.
4. Invoke the increaseBpm function and the decreaseBpm function and console.log the results.
5. Include a new key in heart object called 'color', and set the value to "red".
6. Make a function inside the heart object that changes the color to a value of the user's choosing.
7. Invoke the color function and set the color to 'black', and console.log the color.
8. 🎯 Commit -m "Commit 5: Object Skills"

Challenge 6: The Final Challenge!

You're almost done! You've had a good warm up with Javascript basics. Now let's solidify your knowledge with the ALL concepts you've learned so far.

Answer the questions in script.js in the form of a comment (short answers).

1. List at least 5 properties built into a string.
2. What does running git status do?
3. In your own words, what is type coercion in Javascript?
4. What is the difference between == and === ?
5. What command line shortcut lets me see what directory I'm currently in?
6. What's the difference between forking and cloning in Github?
7. What's the difference between a while loop and a do while loop?
8. 🎯 Commit -m "Commit 6: Object Skills"

Achievement Unlocked: Ninja Warrior Status!

Reach Goals

Reach Goals are not required for homework completion, but I highly recommend you try to master them all! Sharpen those skills!

1. Write a for loop that counts from 0 (inclusive) to 1857 (exclusive) and calculates the sum of all of those numbers, storing the result in the variable reachGoalOne.

• 🎯 Commit -m "Commit 7: Reach 1 Done"

2. Write a while loop that increases count by 12 when it's strictly below 95, decreases it by 7 when it's strictly above 105, and stops as soon as count equals or falls between those two values.

• 🎯 Commit -m "Commit 8: Reach 2 Done"

2. Using whatever code you like, calculate n^n for each value from n from 1 to 10 (both inclusive), and store the sum in the variable reachGoalThree.

• 🎯 Commit -m "Commit 9: No one can defeat me!"

Submitting Your Work

When you're ready, create an issue on the class repo with a title in the format "First and Last Name -- Week XX Day XX". The issue body should have:

• A link to your forked repo (ie. to your homework folder)
• A 'comfort' score on how you feel about your answers, from 1 (very uncomfortable) to 5 (very comfortable)
• A 'completeness' score, from 1 (didn't do it) to 5 (finished all of it)
• A 'win'
• A 'struggle'
• A 'comment'