London | 26-ITP-Jan | Johnny Vargas | Sprint 1 | Coursework

Sprint-1/1-key-exercises/1-count.js

@@ -4,3 +4,6 @@ count = count + 1;
 
 // Line 1 is a variable declaration, creating the count variable with an initial value of 0
 // Describe what line 3 is doing, in particular focus on what = is doing
+
+// Line 3 is having the computer update the current "count" which is 0, with a "+ 1."
+// So now the current count becomes 1.

Sprint-1/1-key-exercises/2-initials.js

@@ -5,7 +5,8 @@ let lastName = "Johnson";
 // Declare a variable called initials that stores the first character of each string.
 // This should produce the string "CKJ", but you must not write the characters C, K, or J in the code of your solution.
 
-let initials = ``;
+let initials = firstName[0] + middleName[0] + lastName[0];
 
 // https://www.google.com/search?q=get+first+character+of+string+mdn
 
+console.log(initials);

Sprint-1/1-key-exercises/3-paths.js

@@ -17,7 +17,10 @@ console.log(`The base part of ${filePath} is ${base}`);
 // Create a variable to store the dir part of the filePath variable
 // Create a variable to store the ext part of the variable
 
-const dir = ;
-const ext = ;
+const dir = filePath.slice(0, lastSlashIndex);
+const ext = filePath.slice(filePath.lastIndexOf("."));
 
-// https://www.google.com/search?q=slice+mdn
+// https://www.google.com/search?q=slice+mdn
+
+console.log(dir)
+console.log(ext)

Sprint-1/1-key-exercises/4-random.js

@@ -7,3 +7,11 @@ const num = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum;
 // Try breaking down the expression and using documentation to explain what it means
 // It will help to think about the order in which expressions are evaluated
 // Try logging the value of num and running the program several times to build an idea of what the program is doing
+
+
+// This code generates a random whole number between 1 and 100.
+// It starts with a random decimal, multiplies it to get the right range, and chops off the decimals to make it a whole number.
+// Then it adds the minimum to make sure the count starts at 1.
+
+
+console.log("The magic number is: " + num);

Sprint-1/2-mandatory-errors/0.js

@@ -1,2 +1,4 @@
-This is just an instruction for the first activity - but it is just for human consumption
-We don't want the computer to run these 2 lines - how can we solve this problem?
+// This is just an instruction for the first activity - but it is just for human consumption
+// We don't want the computer to run these 2 lines - how can we solve this problem?
+
+// We can comment it out by using "//"

Sprint-1/2-mandatory-errors/1.js

@@ -1,4 +1,10 @@
 // trying to create an age variable and then reassign the value by 1
 
-const age = 33;
+let age = 33;
 age = age + 1;
+
+console.log(age)
+
+// The error "Assignment to constant variable" occurs because const is used to declare a constant value that cannot be changed.
+// Since the code tries to reassign the value on line 4 (age = age + 1), the program crashes.
+// To fix this, we would use let, which allows for variable reassignment.

Sprint-1/2-mandatory-errors/2.js

@@ -1,5 +1,9 @@
 // Currently trying to print the string "I was born in Bolton" but it isn't working...
 // what's the error ?
 
-console.log(`I was born in ${cityOfBirth}`);
 const cityOfBirth = "Bolton";
+console.log(`I was born in ${cityOfBirth}`);
+
+
+// The 'ReferenceError' occurs because the code tries to use the variable cityOfBirth before it has been defined.
+// JavaScript reads from top to bottom, so the variable must be declared BEFORE it is called in the console.log.

Sprint-1/2-mandatory-errors/3.js

@@ -1,9 +1,16 @@
 const cardNumber = 4533787178994213;
-const last4Digits = cardNumber.slice(-4);
+const last4Digits = Number(cardNumber.toString().slice(-4));
 
 // The last4Digits variable should store the last 4 digits of cardNumber
 // However, the code isn't working
 // Before running the code, make and explain a prediction about why the code won't work
 // Then run the code and see what error it gives.
 // Consider: Why does it give this error? Is this what I predicted? If not, what's different?
 // Then try updating the expression last4Digits is assigned to, in order to get the correct value
+
+
+// I predict an error will happen because cardNumber is a number and not a string and slice can not be used for pure numbers.
+// We can fix it by turning the number into a string by using .toString() before we slice it.
+
+console.log("The last four digits are: " + last4Digits);
+console.log("This is a " + typeof last4Digits)

Sprint-1/2-mandatory-errors/4.js

@@ -1,2 +1,8 @@
-const 12HourClockTime = "20:53";
-const 24hourClockTime = "08:53";
+const hourClockTime12 = "20:53";
+const hourClockTime24 = "08:53";
+
+// In JavaScript, variable names aren't allowed to start with a number.
+// The computer gets confused because it thinks 12 is a value, not a name.
+// To fix it, we have to start the name with a letter, like clockTime12Hour or just twelveHourClockTime.
+
+console.log(hourClockTime12 + " | " + hourClockTime24);

Sprint-1/3-mandatory-interpret/1-percentage-change.js

@@ -2,7 +2,7 @@ let carPrice = "10,000";
 let priceAfterOneYear = "8,543";
 
 carPrice = Number(carPrice.replaceAll(",", ""));
-priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ""));
+priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", ""));
 
 const priceDifference = carPrice - priceAfterOneYear;
 const percentageChange = (priceDifference / carPrice) * 100;
@@ -12,11 +12,19 @@ console.log(`The percentage change is ${percentageChange}`);
 // Read the code and then answer the questions below
 
 // a) How many function calls are there in this file? Write down all the lines where a function call is made
+// 4, 5, 10.
 
 // b) Run the code and identify the line where the error is coming from - why is this error occurring? How can you fix this problem?
+// It is coming from line 5. Because ("," "") is missing a comma separating the strings.
 
 // c) Identify all the lines that are variable reassignment statements
+// 4, 5.
 
 // d) Identify all the lines that are variable declarations
+// 1, 2, 7 , 8.
 
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+// JavaScript can't do math with commas.
+// replaceAll(",", "") part finds the , in "10,000" and turns it into nothing "", turning the String into "10000".
+// Even without the comma, it's still a String (text). The number part converts the text "10000" into the actual Number 10000.
+// The purpose is so it turns a string of numbers into actual numbers to do math with.

Sprint-1/3-mandatory-interpret/2-time-format.js

@@ -1,4 +1,4 @@
-const movieLength = 8784; // length of movie in seconds
+const movieLength = 3434444; // length of movie in seconds
 
 const remainingSeconds = movieLength % 60;
 const totalMinutes = (movieLength - remainingSeconds) / 60;
@@ -12,14 +12,25 @@ console.log(result);
 // For the piece of code above, read the code and then answer the following questions
 
 // a) How many variable declarations are there in this program?
+// There are 6. (6 Const in this case)
 
 // b) How many function calls are there?
+// 1, the last console.log(result)
 
 // c) Using documentation, explain what the expression movieLength % 60 represents
 // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators
+// movieLength % 60 represents the seconds/minutes left over after you divide the total seconds/minutes by 60
 
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
+// This expression calculates the total number of whole minutes in the movie.
+// It subtracts the "leftover" seconds so you have a number perfectly divisible by 60.
+// It divides by 60 to convert seconds into minutes.
 
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
+// The variable result represents the formatted time string in HH:MM:SS (Hours:Minutes:Seconds) format.
+// A better name for it could be movieLengthFormatted.
 
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+// If any digit ends up being a single digit like "5", the result will look something like 2:26:5. It makes it look unprofessional compared to say 02:26:05.
+// If the movieLength is small like "44", the result will look like 0:0:44, instead of a personally preferable 00:00:44.
+// If the movieLength is huge like "3434444", the result will look like 954:0:44, maybe one solution here could be padding 0's to the highest count of digits, but that could cause further problems depending how this result is shown to the user, maybe instead another solution could be just only allow hours to max out at 99.

Sprint-1/3-mandatory-interpret/3-to-pounds.js

@@ -1,4 +1,4 @@
-const penceString = "399p";
+const penceString = "104569p";
 
 const penceStringWithoutTrailingP = penceString.substring(
   0,
@@ -25,3 +25,8 @@ console.log(`£${pounds}.${pence}`);
 
 // To begin, we can start with
 // 1. const penceString = "399p": initialises a string variable with the value "399p"
+// 2. const penceStringWithoutTrailingP = penceString.substring(0, penceString.length - 1): Removes the "p" from the end.
+// 3. const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0"): Makes the string at least 3 letters long by adding "0"s to the front.
+// 4. const pounds = paddedPenceNumberString.substring(0, paddedPenceNumberString.length - 2): Grabs everything except the last two digits to find the "pound" amount.
+// 5. const pence = paddedPenceNumberString.substring(paddedPenceNumberString.length - 2).padEnd(2, "0"): Grabs exactly the last two digits.
+// 6. console.log(`£${pounds}.${pence}`): Combines the pounds and pence with a decimal point and a "£" symbol.

Sprint-1/4-stretch-explore/chrome.md

@@ -12,7 +12,14 @@ invoke the function `alert` with an input string of `"Hello world!"`;
 
 What effect does calling the `alert` function have?
 
+- It pops up an alert box with the text Hello world! in it.
+- I want to specify this did not work until I formatted it as "alert("Hello world!")
+
 Now try invoking the function `prompt` with a string input of `"What is your name?"` - store the return value of your call to `prompt` in an variable called `myName`.
 
 What effect does calling the `prompt` function have?
 What is the return value of `prompt`?
+
+- Calling "prompt" brings up a box for me to insert text.
+- The return value of "prompt" is whatever was inserted in the box.
+- I input "let myName = prompt("What is your name?")" so it could store the name used. 

Sprint-1/4-stretch-explore/objects.md

@@ -6,11 +6,20 @@ Open the Chrome devtools Console, type in `console.log` and then hit enter
 
 What output do you get?
 
+- I get "ƒ log() { [native code] }"
+
 Now enter just `console` in the Console, what output do you get back?
 
+- I get "console {debug: ƒ, error: ƒ, info: ƒ, log: ƒ, warn: ƒ, …}"
+
 Try also entering `typeof console`
 
+- I get "'object'"
+
 Answer the following questions:
 
 What does `console` store?
+- Console stores various data, like "debug", "error", "info", "log" & "warn"
+
 What does the syntax `console.log` or `console.assert` mean? In particular, what does the `.` mean?
+- The "." means for it to look inside for information using the tool written on the right.