diff --git a/Sprint-1/1-key-exercises/1-count.js b/Sprint-1/1-key-exercises/1-count.js index 117bcb2b6e..fe259ade0f 100644 --- a/Sprint-1/1-key-exercises/1-count.js +++ b/Sprint-1/1-key-exercises/1-count.js @@ -3,4 +3,4 @@ let count = 0; 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 adds 1 to the current value of count and assigns the result back to count using the = operator. \ No newline at end of file diff --git a/Sprint-1/1-key-exercises/2-initials.js b/Sprint-1/1-key-exercises/2-initials.js index 47561f6175..a665e31ec1 100644 --- a/Sprint-1/1-key-exercises/2-initials.js +++ b/Sprint-1/1-key-exercises/2-initials.js @@ -4,8 +4,10 @@ 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. +// [0] accesses the first character of each string and combines them to create the initials. +// Using template literals (backticks) allows us to easily concatenate the characters together into a single string. -let initials = ``; +let initials = `${firstName[0]}${middleName[0]}${lastName[0]}`; // https://www.google.com/search?q=get+first+character+of+string+mdn diff --git a/Sprint-1/1-key-exercises/3-paths.js b/Sprint-1/1-key-exercises/3-paths.js index ab90ebb28e..b96e4cd6a5 100644 --- a/Sprint-1/1-key-exercises/3-paths.js +++ b/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(0, lastSlashIndex); +const ext = base.slice(base.lastIndexOf(".") + 1); // https://www.google.com/search?q=slice+mdn \ No newline at end of file diff --git a/Sprint-1/1-key-exercises/4-random.js b/Sprint-1/1-key-exercises/4-random.js index 292f83aabb..f9aa068dd1 100644 --- a/Sprint-1/1-key-exercises/4-random.js +++ b/Sprint-1/1-key-exercises/4-random.js @@ -4,6 +4,14 @@ 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? +//num becomes A random whole number between 1 and 100. + // 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 + +// Math.random() creates a random decimal number. +// The number will always be between 0 and 1, but it will never actually reach 1. + +// Math.floor() rounds down the decimal number that is created after +// Math.random() is multiplied by the range. \ No newline at end of file diff --git a/Sprint-1/2-mandatory-errors/0.js b/Sprint-1/2-mandatory-errors/0.js index cf6c5039f7..6a7a7f6908 100644 --- a/Sprint-1/2-mandatory-errors/0.js +++ b/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? \ No newline at end of file +// 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? \ No newline at end of file diff --git a/Sprint-1/2-mandatory-errors/1.js b/Sprint-1/2-mandatory-errors/1.js index 7a43cbea76..0e28fbabe2 100644 --- a/Sprint-1/2-mandatory-errors/1.js +++ b/Sprint-1/2-mandatory-errors/1.js @@ -1,4 +1,5 @@ // trying to create an age variable and then reassign the value by 1 +// A const variable cannot be reassigned.It it constant -const age = 33; +let age = 33; age = age + 1; diff --git a/Sprint-1/2-mandatory-errors/2.js b/Sprint-1/2-mandatory-errors/2.js index e09b89831d..0d1f2aaee5 100644 --- a/Sprint-1/2-mandatory-errors/2.js +++ b/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 ? +// what's the error ? - The variable is being used before it's declared -console.log(`I was born in ${cityOfBirth}`); const cityOfBirth = "Bolton"; +console.log(`I was born in ${cityOfBirth}`); diff --git a/Sprint-1/2-mandatory-errors/3.js b/Sprint-1/2-mandatory-errors/3.js index ec101884db..a183ea742f 100644 --- a/Sprint-1/2-mandatory-errors/3.js +++ b/Sprint-1/2-mandatory-errors/3.js @@ -1,9 +1,19 @@ const cardNumber = 4533787178994213; -const last4Digits = cardNumber.slice(-4); +// I fixed the error by replacing the original expression instead of declaring +// last4Digits a second time. Declaring a const twice causes a SyntaxError. +const last4Digits = cardNumber % 10000; // 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 +// .Slice only works on strings, not numbers. Therefore, the code will throw an error + // Then run the code and see what error it gives. +// Uncaught TypeError: cardNumber.slice is not a function + // Consider: Why does it give this error? Is this what I predicted? If not, what's different? +// The error is what I predicted. The slice method is not a function that can be used on numbers, only strings. + // Then try updating the expression last4Digits is assigned to, in order to get the correct value + diff --git a/Sprint-1/2-mandatory-errors/4.js b/Sprint-1/2-mandatory-errors/4.js index 5f86c730bc..26e7ec01b8 100644 --- a/Sprint-1/2-mandatory-errors/4.js +++ b/Sprint-1/2-mandatory-errors/4.js @@ -1,2 +1,4 @@ -const 12HourClockTime = "8:53pm"; -const 24hourClockTime = "20:53"; +const twelveHourClockTime = "8:53pm"; +const twentyFourHourClockTime = "20:53"; + +// Variable names cannot start with a number, so the variable name "24HourClockTime" and "12HourClockTime" is invalid. \ No newline at end of file diff --git a/Sprint-1/3-mandatory-interpret/1-percentage-change.js b/Sprint-1/3-mandatory-interpret/1-percentage-change.js index e24ecb8e18..80cdac2840 100644 --- a/Sprint-1/3-mandatory-interpret/1-percentage-change.js +++ b/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 +12,20 @@ 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 +// There are 5 function calls in this file. +// Line 4 calls replaceAll() and Number(). +// Line 5 calls replaceAll() and Number(). +// Line 10 calls console.log(). // 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? +// I changed the value from a string to a number by wrapping the replaceAll() result in Number(). // c) Identify all the lines that are variable reassignment statements +// Lines 4 and 5 are variable reassignment statements because its declared on lines 1 and 2. + // d) Identify all the lines that are variable declarations +// Lines 1, 2, 7, and 8 are variable declarations because they declare variables using let and const. // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression? +//// Removes commas and converts the string to a number. diff --git a/Sprint-1/3-mandatory-interpret/2-time-format.js b/Sprint-1/3-mandatory-interpret/2-time-format.js index 47d2395587..4a0be372de 100644 --- a/Sprint-1/3-mandatory-interpret/2-time-format.js +++ b/Sprint-1/3-mandatory-interpret/2-time-format.js @@ -1,4 +1,4 @@ -const movieLength = 8784; // length of movie in seconds +const movieLength = 3665; // length of movie in seconds const remainingSeconds = movieLength % 60; const totalMinutes = (movieLength - remainingSeconds) / 60; @@ -12,14 +12,30 @@ 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? +/* 6 - movieLength +remainingSeconds +totalMinutes +remainingMinutes +totalHours +result */ // b) How many function calls are there? +// 1, console.log() is the only function call in this program // c) Using documentation, explain what the expression movieLength % 60 represents // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators +// % returns the remainder. // d) Interpret line 4, what does the expression assigned to totalMinutes mean? +// The expression assigned to totalMinutes is calculating the total number of minutes in the movie length +// by subtracting the remaining seconds from the total movie length and then dividing that value by 60. +// This gives us the total number of whole minutes in the movie length. // e) What do you think the variable result represents? Can you think of a better name for this variable? +// The variable result stores the movie duration as a formatted string (hours:minutes:seconds). +// A better name would be "formattedMovieLength". // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer +// The code works when movieLength is 3665. It outputs "1:1:5", which is correct, +// but the formatting is not ideal. A better formatted output would be "1:01:05". +// The code works for whole numbers, but it does not pad single-digit minutes and seconds with leading zeros. diff --git a/Sprint-1/3-mandatory-interpret/3-to-pounds.js b/Sprint-1/3-mandatory-interpret/3-to-pounds.js index 60c9ace69a..75a97837a0 100644 --- a/Sprint-1/3-mandatory-interpret/3-to-pounds.js +++ b/Sprint-1/3-mandatory-interpret/3-to-pounds.js @@ -25,3 +25,9 @@ console.log(`£${pounds}.${pence}`); // To begin, we can start with // 1. const penceString = "399p": initialises a string variable with the value "399p" +// 2. Removes the trailing "p" from the string. +// 3. Adds leading zeros if needed. +// 4. Extracts the pounds value. +// 5. Extracts the pence value. +// 6. Logs the formatted price (£3.99). +// Final output: "£3.99". \ No newline at end of file diff --git a/Sprint-1/4-stretch-explore/chrome.md b/Sprint-1/4-stretch-explore/chrome.md index e7dd5feafe..ee3467571b 100644 --- a/Sprint-1/4-stretch-explore/chrome.md +++ b/Sprint-1/4-stretch-explore/chrome.md @@ -11,8 +11,12 @@ In the Chrome console, invoke the function `alert` with an input string of `"Hello world!"`; What effect does calling the `alert` function have? +It displays a pop-up message with the text "Hello world!" and waits for the user to close it. 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 displays a dialog box asking the user for input. + What is the return value of `prompt`? +It returns the text the user entered as a string. diff --git a/Sprint-1/4-stretch-explore/objects.md b/Sprint-1/4-stretch-explore/objects.md index 0216dee56a..d64209596e 100644 --- a/Sprint-1/4-stretch-explore/objects.md +++ b/Sprint-1/4-stretch-explore/objects.md @@ -5,12 +5,16 @@ In this activity, we'll explore some additional concepts that you'll encounter i 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? - +console {debug: ƒ, error: ƒ, info: ƒ, log: ƒ, warn: ƒ, …} Try also entering `typeof console` - +" object" Answer the following questions: What does `console` store? +console is an object that stores functions used for debugging and displaying messages. + What does the syntax `console.log` or `console.assert` mean? In particular, what does the `.` mean? +The . accesses a property or method on an object. \ No newline at end of file