Sheffield | 26-ITP-jan | Richard Frimpong | Sprint 1 | Structuring and Testing Data

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

@@ -1,6 +1,10 @@
+// This script shows how a counter changes step by step.
+
 let count = 0;
 
+// Line 3 increments the current value of count by 1.
+// It takes the current value of count (0), adds 1 to it,
+// and assigns the result (1) back to the count variable.
 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
+console.log(count);

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

@@ -5,7 +5,16 @@ 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 = ``;
+
+// Solution logic
+
+// We want to combine those characters into one string.
+
+// So we concatenate:
+
+let initials = firstName[0] + middleName[0] + lastName[0];
+console.log(initials);
 
 // https://www.google.com/search?q=get+first+character+of+string+mdn
 

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

@@ -17,7 +17,15 @@ 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 = ;
+//const ext = ;
+
+const dir = filePath.slice(0, lastSlashIndex);
+
+const lastDotIndex = filePath.lastIndexOf(".");
+const ext = filePath.slice(lastDotIndex);
+
+console.log(`Dir: ${dir}`);
+console.log(`Ext: ${ext}`);
 
 // https://www.google.com/search?q=slice+mdn

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

@@ -3,7 +3,10 @@ const maximum = 100;
 
 const num = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum;
 
-// In this exercise, you will need to work out what num represents?
-// 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
+console.log(num);
+
+// num is a random integer between 1 and 100 (inclusive).
+// Math.random() returns a decimal in the range [0, 1).
+// Multiplying by (maximum - minimum + 1) scales it to the size of the range.
+// Math.floor(...) converts it to an integer.
+// Adding minimum shifts the range to start at 1 instead of 0.

Sprint-1/2-mandatory-errors/answers.md

@@ -0,0 +1,49 @@
+# Sprint 1 — Mandatory Errors (Explanations)
+
+## 0.js
+- Error shown:
+- Why it happens:
+- MDN link (optional):
+- Error shown: `SyntaxError: Unexpected identifier 'is'` on line 1.
+- Why it happens: The file begins with plain English text that is not inside a comment or a quoted string. Node tries to interpret it as JavaScript code, but `This is ...` is not valid JS syntax, so parsing fails.
+- MDN link (optional): https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Errors/Unexpected_token
+
+## 1.js
+- Error shown:
+- Why it happens:
+- MDN link (optional):
+- Error shown: `TypeError: Assignment to constant variable.` on line 4.
+- Why it happens: The variable `age` was declared with `const`, which prevents reassignment. The statement `age = age + 1` attempts to update the value, causing the error.
+- MDN link (optional): https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/const
+
+## 2.js
+- Error shown:
+- Why it happens:
+- MDN link (optional):
+- Error shown: `ReferenceError: Cannot access 'cityOfBirth' before initialization`.
+- Why it happens: The variable `cityOfBirth` is declared later in the file using `let` or `const`, but it is used before that declaration. JavaScript does not allow access to `let`/`const` variables before initialization (temporal dead zone).
+- MDN link: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Errors/Cant_access_lexical_declaration_before_init
+
+
+## 3.js
+- Error shown:
+- Why it happens:
+- MDN link (optional):
+### 3.js
+
+- Error shown: `TypeError: cardNumber.slice is not a function`
+- Why it happens: The variable `cardNumber` is a number, and numbers do not have the `slice()` method. The `slice()` method is only available on strings and arrays.
+- Concept: Methods depend on data types in JavaScript.
+- MDN link: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/slice
+
+
+## 4.js
+- Error shown:
+- Why it happens:
+- MDN link (optional):
+### 4.js
+
+- Error shown: `SyntaxError: Invalid or unexpected token`
+- Why it happens: The variable name `12HourClockTime` starts with a number. JavaScript identifiers cannot begin with a digit, so the parser throws a syntax error.
+- Concept: Variable naming rules (identifiers must start with a letter, `_`, or `$`)
+- MDN link: https://developer.mozilla.org/en-US/docs/Glossary/Identifier

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

@@ -2,8 +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;
 

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

@@ -22,4 +22,4 @@ console.log(result);
 
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
 
-// f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+// f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer

Sprint-1/3-mandatory-interpret/answers.md

@@ -0,0 +1,156 @@
+# Sprint 1 — Mandatory Interpret (Notes)
+
+## 1-percentage-change.js
+- What the program does:
+- Inputs:
+- Output:
+- Unfamiliar syntax (with link):
+- What I changed / why:
+
+
+## 2-time-format.js
+- What the program does:
+- Inputs:
+- Output:
+- Unfamiliar syntax (with link):
+- What I changed / why:
+
+## 3-to-pounds.js
+- What the program does:
+- Inputs:
+- Output:
+- Unfamiliar syntax (with link):
+- What I changed / why:
+
+
+## 1-percentage-change.js
+
+### a) How many function calls are there?
+There are 5 function calls:
+- Number(carPrice.replaceAll(",", ""))
+- carPrice.replaceAll(",", "")
+- Number(priceAfterOneYear.replaceAll(",", ""))
+- priceAfterOneYear.replaceAll(",", "")
+- console.log(...)
+
+---
+
+### b) Where did the error occur and why?
+The error occurred on the line:
+priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ""));
+
+The replaceAll function was missing a comma between its arguments. The correct syntax requires two arguments: replaceAll(search, replacement).
+
+Fix:
+priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", ""));
+
+---
+
+### c) Variable reassignment statements
+- carPrice = Number(carPrice.replaceAll(",", ""))
+- priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", ""))
+
+---
+
+### d) Variable declarations
+- let carPrice = "10,000"
+- let priceAfterOneYear = "8,543"
+- const priceDifference = carPrice - priceAfterOneYear
+- const percentageChange = (priceDifference / carPrice) * 100
+
+---
+
+### e) What does Number(carPrice.replaceAll(",", "")) do?
+First, replaceAll(",", "") removes commas from the string "10,000", producing "10000".
+Then, Number(...) converts the string "10000" into the numeric value 10000.
+This ensures arithmetic operations can be performed correctly.
+
+
+
+## 2-time-format.js
+
+### a) How many variable declarations?
+There are 6 variable declarations:
+- movieLength
+- remainingSeconds
+- totalMinutes
+- remainingMinutes
+- totalHours
+- result
+
+---
+
+### b) How many function calls?
+There is 1 function call:
+- console.log(result)
+
+---
+
+### c) What does movieLength % 60 represent?
+The % operator returns the remainder after division.
+movieLength % 60 gives the number of seconds left after converting full minutes.
+In this example, it returns 24 seconds.
+
+---
+
+### d) Interpret line 4 (totalMinutes)
+const totalMinutes = (movieLength - remainingSeconds) / 60;
+
+This subtracts the leftover seconds from the total seconds and divides by 60.
+The result is the total number of full minutes in the movie.
+
+---
+
+### e) What does result represent? Better name?
+The variable result represents the formatted movie duration in hours:minutes:seconds.
+A better name could be:
+- formattedTime
+- movieDuration
+- durationString
+
+---
+
+### f) Will this work for all values of movieLength?
+Yes, it works for any positive number of seconds.
+However, if movieLength is negative, a decimal, or not a number, the result would be incorrect.
+Also, minutes and seconds are not padded with leading zeros, so values like 2:3:5 may appear instead of 02:03:05.
+
+
+
+
+## 3-to-pounds.js
+
+1) `const penceString = "399p";`
+- Declares a string containing a price in pence, with a trailing `p` character.
+
+2) `const penceStringWithoutTrailingP = penceString.substring(0, penceString.length - 1);`
+- Takes a substring from index 0 up to (but not including) the last character.
+- Purpose: remove the trailing `"p"`.
+- For `"399p"`, this becomes `"399"`.
+
+3) `const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");`
+- Pads the string on the left until it is at least length 3, using `"0"`.
+- Purpose: make sure we always have enough digits to represent pounds + pence.
+- Example: `"5"` becomes `"005"`, `"50"` becomes `"050"`, `"399"` stays `"399"`.
+
+4) `const pounds = paddedPenceNumberString.substring(0, paddedPenceNumberString.length - 2);`
+- Takes everything except the last 2 digits.
+- Purpose: the part before the last 2 digits is the pounds.
+- For `"399"`, length is 3, so substring(0, 1) → `"3"`.
+
+5) `const pence = paddedPenceNumberString.substring(paddedPenceNumberString.length - 2).padEnd(2, "0");`
+- First, `substring(paddedPenceNumberString.length - 2)` takes the last 2 characters.
+- Because `paddedPenceNumberString` has already been padded earlier with `padStart(3, "0")`, it will always be at least 3 characters long.
+- That means the substring operation already returns exactly 2 characters for any valid `penceString`.
+- So `.padEnd(2, "0")` is not actually needed in this script.
+- For `"399"`, the last two digits are `"99"`, so the result stays `"99"`.
+
+6) `console.log(\`£${pounds}.${pence}\`);`
+- Uses a template literal to format the final currency string as pounds and pence.
+- For pounds `"3"` and pence `"99"` → outputs `£3.99`.
+
+### Unfamiliar syntax (docs)
+- substring: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/substring
+- padStart: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/padStart
+- padEnd: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/padEnd
+- template literals: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Template_literals

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

@@ -0,0 +1,72 @@
+## chrome.md
+
+### What the task asked me to do
+Explore the Chrome DevTools console and investigate what the console object stores and how dot notation works.
+
+---
+
+### What I did (steps)
+1. Opened Chrome DevTools and navigated to the Console tab.
+2. Entered `console.log` and observed that it returned a function.
+3. Entered `console` and observed that it returned an object with multiple methods such as log, warn, error, and assert.
+4. Entered `typeof console` and confirmed that console is an object.
+
+---
+
+### What I learned
+- `console` stores an object containing many methods used for debugging.
+- `console.log`, `console.assert`, etc. are functions stored inside the console object.
+- The `.` operator is called dot notation and is used to access properties or methods of an object.
+
+---
+
+### Useful links
+- https://developer.mozilla.org/en-US/docs/Web/API/Console
+- https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects
+
+
+
+## objects.md
+
+### What output did I get?
+
+- `console.log` → returned a function definition (ƒ log() { [native code] })
+- `console` → returned an object with many methods such as log, warn, error, assert
+- `typeof console` → returned "object"
+
+---
+
+### What does `console` store?
+The console variable stores an object that contains multiple debugging methods. These methods allow developers to print messages, warnings, errors, and other diagnostic information in the browser console.
+
+---
+
+### What does `console.log` or `console.assert` mean?
+These expressions use dot notation to access methods inside the console object.
+For example:
+- `console.log` accesses the log function
+- `console.assert` accesses the assert function
+
+---
+
+### What does the `.` mean?
+The dot operator is called dot notation.
+It is used to access properties or methods of an object.
+
+So:
+- `console` is the object
+- `log` is a method inside that object
+- `console.log` means "access the log method from the console object"
+
+---
+
+### What I learned
+- Objects store related data and functions together
+- The browser console itself is an object
+- Dot notation is how we interact with object properties and methods
+
+---
+
+### Useful links
+- https://developer.mozilla.org/en-US/docs/Web/API/Console
+- https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects

Sprint-1/notes/learning-log.md

@@ -0,0 +1,16 @@
+# Sprint 1 — Learning Log
+
+## What I learned
+- Started Sprint 1 exercises and set up coursework branch
+- Learned how to extract directory and extension from a file path using lastIndexOf and slice.
+- How Math.random(), Math.floor(), and arithmetic combine to generate a random integer in a range
+
+
+## Errors I hit and what they mean## What I learned
+
+
+## Docs I used (links)
+- 
+
+## Questions for class
+-