diff --git a/Sprint-1/1-key-exercises/1-count.js b/Sprint-1/1-key-exercises/1-count.js index 117bcb2b6..df2f6c153 100644 --- a/Sprint-1/1-key-exercises/1-count.js +++ b/Sprint-1/1-key-exercises/1-count.js @@ -4,3 +4,4 @@ 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 updating the value of count by adding 1 to its current value. The = operator is an assignment operator, which assigns the result of the expression on the right (count + 1) to the variable on the left (count). So, after line 3 is executed, count will have a new value that is one greater than its previous value. \ 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 47561f617..cfae9aae2 100644 --- a/Sprint-1/1-key-exercises/2-initials.js +++ b/Sprint-1/1-key-exercises/2-initials.js @@ -5,7 +5,7 @@ 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 diff --git a/Sprint-1/1-key-exercises/3-paths.js b/Sprint-1/1-key-exercises/3-paths.js index ab90ebb28..93c046970 100644 --- a/Sprint-1/1-key-exercises/3-paths.js +++ b/Sprint-1/1-key-exercises/3-paths.js @@ -17,7 +17,8 @@ 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(".") + 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 292f83aab..eeffdb290 100644 --- a/Sprint-1/1-key-exercises/4-random.js +++ b/Sprint-1/1-key-exercises/4-random.js @@ -7,3 +7,6 @@ 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 + +//Math.random() returns a random number between 0 and 1 but not including 1. By multiplying by (maximum-minimum +1) we get a random number between 0 and 100. +// The answer could however be in decimal point, thereofor by using Math.floor() we round down to the nearest whole number, but that would give us a range between 0 and 99. Adding minimum (1) to the result gives us a range between 1 and 100 inclusive. \ 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 cf6c5039f..f35d28233 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? - I have added a slash to make it a comment. \ 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 7a43cbea7..d0cc0164f 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 -const age = 33; +let age = 33; age = age + 1; +// use let instead of const to declare the age variable, as const variables cannot be reassigned. \ No newline at end of file diff --git a/Sprint-1/2-mandatory-errors/2.js b/Sprint-1/2-mandatory-errors/2.js index e09b89831..988a468f5 100644 --- a/Sprint-1/2-mandatory-errors/2.js +++ b/Sprint-1/2-mandatory-errors/2.js @@ -1,5 +1,6 @@ // 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}`); + +//you have to define the variable first before you can use it. diff --git a/Sprint-1/2-mandatory-errors/3.js b/Sprint-1/2-mandatory-errors/3.js index ec101884d..0b796f95b 100644 --- a/Sprint-1/2-mandatory-errors/3.js +++ b/Sprint-1/2-mandatory-errors/3.js @@ -1,5 +1,5 @@ const cardNumber = 4533787178994213; -const last4Digits = cardNumber.slice(-4); +const last4Digits = cardNumber.toString().slice(-4); // The last4Digits variable should store the last 4 digits of cardNumber // However, the code isn't working @@ -7,3 +7,5 @@ const last4Digits = cardNumber.slice(-4); // 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 + +// The error is because the slice method is being called on a number, but slice is a string method. To fix this, we can convert the cardNumber to a string before calling slice. I have fixed it by using the toString() method. \ No newline at end of file diff --git a/Sprint-1/2-mandatory-errors/4.js b/Sprint-1/2-mandatory-errors/4.js index 21dad8c5d..0890ff36d 100644 --- a/Sprint-1/2-mandatory-errors/4.js +++ b/Sprint-1/2-mandatory-errors/4.js @@ -1,2 +1,2 @@ -const 12HourClockTime = "20:53"; -const 24hourClockTime = "08:53"; \ No newline at end of file +const twentyFourHourClockTime = "20:53"; +const twelveHourClockTime = "08:53"; \ 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 e24ecb8e1..36fd142f1 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; @@ -11,12 +11,14 @@ 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 +// 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. On line 4,5 and 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 on line 5 which has been fixed. // c) Identify all the lines that are variable reassignment statements - +// Lines 4 and 5. // d) Identify all the lines that are variable declarations - +//Lines 1,2, 7 and 8. // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression? +//It has converted the string "10,000" to a number by first removing the comma using replaceAll() method and then converting the resulting string to a number using the Number() function. This allows us to perform mathematical operations on the carPrice variable. \ No newline at end of file diff --git a/Sprint-1/3-mandatory-interpret/2-time-format.js b/Sprint-1/3-mandatory-interpret/2-time-format.js index 47d239558..3bed1f6ba 100644 --- a/Sprint-1/3-mandatory-interpret/2-time-format.js +++ b/Sprint-1/3-mandatory-interpret/2-time-format.js @@ -12,14 +12,20 @@ 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 variable declarations. // b) How many function calls are there? +//1 function call, on line 10. // c) Using documentation, explain what the expression movieLength % 60 represents // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators +//The remainder operator returns the remainder left over when movieLength is divided by 60. // d) Interpret line 4, what does the expression assigned to totalMinutes mean? +// The expression (movieLength - remainingSeconds) / 60 calculates the total number of whole minutes in the movie length. It first subtracts the remaining seconds from the total movie length to get a value that is a multiple of 60, and then divides that value by 60 to convert it from seconds to minutes. It gives it as a whole number and is easier to work with. // e) What do you think the variable result represents? Can you think of a better name for this variable? +// It represents the movie duration in the format of hours:minutes:seconds. A better name for this variable could be movieDuration. // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer +// It does not work for negative values. The code assumes that movieLength is a positive integer representing the length of a movie in seconds. If movieLength is negative, the calculations for remainingSeconds, totalMinutes, remainingMinutes, and totalHours will not produce meaningful results, and the final result will not represent a valid time format. \ No newline at end of file diff --git a/Sprint-1/3-mandatory-interpret/3-to-pounds.js b/Sprint-1/3-mandatory-interpret/3-to-pounds.js index 60c9ace69..fd0de613a 100644 --- a/Sprint-1/3-mandatory-interpret/3-to-pounds.js +++ b/Sprint-1/3-mandatory-interpret/3-to-pounds.js @@ -25,3 +25,8 @@ console.log(`£${pounds}.${pence}`); // To begin, we can start with // 1. const penceString = "399p": initialises a string variable with the value "399p" +//2. const penceStringWithoutTrailingP = penceString.substring(0, penceString.length - 1): removes the trailing "p" from the penceString to get just the numeric part of the price in pence. +//3. const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0"): Ensures that the string always has 3 numbers by adding zeroes to the string if less than 3 characters. +//4. const pounds = paddedPenceNumberString.substring(0, paddedPenceNumberString.length - 2): Extracts the pounds part of the string. The last two digits are pence but the first is pounds. +//5. const pence = paddedPenceNumberString.substring(paddedPenceNumberString.length - 2).padEnd(2, "0"): Extracts the pence part of the string and ensures its always two digits by adding zeroes when needed. +//6. console.log(`£${pounds}.${pence}`): Outputs the final price in pounds and pence format. \ 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 e7dd5feaf..fd4a26c62 100644 --- a/Sprint-1/4-stretch-explore/chrome.md +++ b/Sprint-1/4-stretch-explore/chrome.md @@ -11,8 +11,10 @@ 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 the input string. 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 the question and asks for your input. What is the return value of `prompt`? +The name the user enters. \ No newline at end of file diff --git a/Sprint-1/4-stretch-explore/objects.md b/Sprint-1/4-stretch-explore/objects.md index 0216dee56..43682b973 100644 --- a/Sprint-1/4-stretch-explore/objects.md +++ b/Sprint-1/4-stretch-explore/objects.md @@ -5,12 +5,18 @@ 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? +I get this: ƒ log() { [native code] } Now enter just `console` in the Console, what output do you get back? +I get this: 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 is an object that lets you print messages, errors, warnings etc + What does the syntax `console.log` or `console.assert` mean? In particular, what does the `.` mean? +console.log allows you to print messages while assert checks a condition.