Sheffield | 25-ITP-SEP | Jak Rhodes-Smith | Sprint 1 | coursework/sprint-1

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

@@ -4,3 +4,5 @@ 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 reassigning the 'count' variable to it's initial value plus one

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.charAt(0) + middleName.charAt(0) + lastName.charAt(0)
+}`;
 
 // https://www.google.com/search?q=get+first+character+of+string+mdn
-

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

@@ -17,7 +17,7 @@ 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(1, lastSlashIndex);
+const ext = base.split(".")[1];
 
-// https://www.google.com/search?q=slice+mdn
+// https://www.google.com/search?q=slice+mdn

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

@@ -7,3 +7,19 @@ 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
+
+// The num variable will evaluate to a random number between the minimum and maximum values
+
+// Math.random()
+// Random decimal number (0 - 1)
+
+// (maximum - minimum + 1)
+// The size of the range
+
+// Math.random() * (maximum - minimum + 1)
+// Random decimal (0 - 100)
+
+// Math.floor(...)
+// Rounds the result down to a whole number (0 - 99)
+
+// Adding minimum shifts the range up, so the final result is between the minimum and maximum (1 - 100 inclusive)

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

@@ -1,2 +1,2 @@
-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?

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

@@ -1,4 +1,4 @@
 // trying to create an age variable and then reassign the value by 1
 
-const age = 33;
+let age = 33;
 age = age + 1;

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

@@ -1,5 +1,5 @@
 // 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}`);

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

@@ -1,9 +1,11 @@
 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
+
+// .slice() will only work on arrays or strings

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

@@ -1,2 +1,2 @@
-const 12HourClockTime = "20:53";
-const 24hourClockTime = "08:53";
+const twelveHourClockTime = "20:53";
+const twentyFourHourClockTime = "08:53";

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;
@@ -13,10 +13,31 @@ console.log(`The percentage change is ${percentageChange}`);
 
 // a) How many function calls are there in this file? Write down all the lines where a function call is made
 
+// carPrice.replaceAll(",", "") (line 4)
+// Number(carPrice.replaceAll(",", "")) (line 4)
+// priceAfterOneYear.replaceAll(",", "") (line 5)
+// Number(priceAfterOneYear.replaceAll(",", "")) (line 5)
+// console.log(`The percentage change is ${percentageChange}`) (line 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?
 
+// Syntax error - Arguments need to be separated by a comma
+
 // c) Identify all the lines that are variable reassignment statements
 
+// carPrice = Number(carPrice.replaceAll(",", "")) (line 4)
+// priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", "")) (line 5)
+
 // d) Identify all the lines that are variable declarations
 
+// let carPrice = "10,000" (line 1)
+// let priceAfterOneYear = "8,543" (line 2)
+// const priceDifference = carPrice - priceAfterOneYear (line 7)
+// const percentageChange = (priceDifference / carPrice) * 100 (line 8)
+
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+
+// (carPrice.replaceAll(",", "")) takes the string stored in the carPrice variable ("10,000") and removes all instances of commas (",")
+// Without this, the result of Number(carPrice) would be NaN (Not a Number)
+
+// Number(...) then takes the edited string ("10000") and converts it to a number (10000) so that numerical operations can be performed on this value

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

@@ -13,13 +13,30 @@ console.log(result);
 
 // a) How many variable declarations are there in this program?
 
+// 6
+
 // b) How many function calls are there?
 
+// 1
+
 // c) Using documentation, explain what the expression movieLength % 60 represents
 // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators
 
+// It gives the remainder left over when one number is divided by another
+
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
 
+// Its subtracts the remainder from the movieLength so that it can be divided into a whole number
+
+// (movieLength - remainingSeconds) / 60
+// 8760 / 60 = 146
+
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
 
+// The variable represents the movie length in seconds converted to a (HH:MM:SS) format
+// A better variable name would be 'formattedTime'
+
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+
+// No, this code will not work for all values of movieLength
+// In edge cases where movieLength is assigned a value of a negative number or string, the output will not make sense

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

@@ -1,20 +1,27 @@
+// 1. initialises a string variable with the value "399p"
 const penceString = "399p";
 
+// 2. removes the trailing 'p' character
 const penceStringWithoutTrailingP = penceString.substring(
   0,
   penceString.length - 1
 );
 
+// 3. pads the numeric string with leading zeros so it is at least 3 digits
 const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");
+
+// 4. extracts the pound part by taking all but the last two digits
 const pounds = paddedPenceNumberString.substring(
   0,
   paddedPenceNumberString.length - 2
 );
 
+// 5. extracts the pence part by taking the last two digits, and pads with trailing zeroes if needed
 const pence = paddedPenceNumberString
   .substring(paddedPenceNumberString.length - 2)
   .padEnd(2, "0");
 
+// 6. formats and prints the result as a pounds and pence string
 console.log(`£${pounds}.${pence}`);
 
 // This program takes a string representing a price in pence

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 opens a dialog box in the browser displaying the message you provide.
+
 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?
+
+It opens a dialog box in the browser that asks the user to input text.
+
 What is the return value of `prompt`?
+
+It returns the text entered by the user as a string, or `null` if the user cancels the prompt.

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

@@ -6,11 +6,19 @@ Open the Chrome devtools Console, type in `console.log` and then hit enter
 
 What output do you get?
 
+`ƒ log() { [native code] }`
+
 Now enter just `console` in the Console, what output do you get back?
 
 Try also entering `typeof console`
 
 Answer the following questions:
 
 What does `console` store?
+
+Various methods and properties (e.g. `log`, `error`, `trace`)
+
 What does the syntax `console.log` or `console.assert` mean? In particular, what does the `.` mean?
+
+The `.` is dot notation used to access a property or method of an object.
+`console.log` means you are accessing the `log` method that belongs to the `console` object.