diff --git a/Sprint-1/1-key-exercises/1-count.js b/Sprint-1/1-key-exercises/1-count.js index 117bcb2b6..0d9c8a880 100644 --- a/Sprint-1/1-key-exercises/1-count.js +++ b/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 an assignment where = is an assignment operator and in there we are adding value of 1 to the count variable diff --git a/Sprint-1/1-key-exercises/2-initials.js b/Sprint-1/1-key-exercises/2-initials.js index 47561f617..f6b16b322 100644 --- a/Sprint-1/1-key-exercises/2-initials.js +++ b/Sprint-1/1-key-exercises/2-initials.js @@ -6,6 +6,6 @@ let lastName = "Johnson"; // 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 = ``; +console.log(`the initials is ${firstName.charAt(0)}, ${middleName.charAt(0), lastName.charAt(0)}`); -// https://www.google.com/search?q=get+first+character+of+string+mdn - +// https://www.google.com/search?q=get+first+character+of+string+mdn \ No newline at end of file diff --git a/Sprint-1/1-key-exercises/3-paths.js b/Sprint-1/1-key-exercises/3-paths.js index ab90ebb28..0014c33ed 100644 --- a/Sprint-1/1-key-exercises/3-paths.js +++ b/Sprint-1/1-key-exercises/3-paths.js @@ -15,9 +15,10 @@ const base = filePath.slice(lastSlashIndex + 1); 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 +// 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 \ No newline at end of file + +// 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..87c0e721d 100644 --- a/Sprint-1/1-key-exercises/4-random.js +++ b/Sprint-1/1-key-exercises/4-random.js @@ -7,3 +7,10 @@ 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.floor will make the number as a whole and remove any decimals or more likely to round the the nearest whole number +// math.random will generate a random number from 0 to 1 but not 1 +// (maximum - minimum + 1) provide a range of generated random number +// num is a random whole number between 1 and 100 + +console.log(num); \ 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..65ad3030d 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 7a43cbea7..031839b47 100644 --- a/Sprint-1/2-mandatory-errors/1.js +++ b/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; diff --git a/Sprint-1/2-mandatory-errors/2.js b/Sprint-1/2-mandatory-errors/2.js index e09b89831..876629966 100644 --- a/Sprint-1/2-mandatory-errors/2.js +++ b/Sprint-1/2-mandatory-errors/2.js @@ -1,5 +1,8 @@ // 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}`); +//const cityOfBirth = "Bolton"; + +// the error is that cityOfBirth varaible declared after the logging command \ No newline at end of file diff --git a/Sprint-1/2-mandatory-errors/3.js b/Sprint-1/2-mandatory-errors/3.js index ec101884d..01b95531d 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.slice(-4); // The last4Digits variable should store the last 4 digits of cardNumber // However, the code isn't working @@ -7,3 +7,6 @@ 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 + +// I predicted the last four digits bit it has to be a string in order to use the method slice and that explain why it wasn't working +const last4Digits = cardNumber.toString.slice(-4); \ 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..f0ab94e12 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 twelveHourClockTime = "20:53"; +const twentyFourHourClockTime = "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..5b036d6c1 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 +12,27 @@ 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 +//1-carPrice.replaceAll(",", "") in line 4 +//3-number(...) in line 4 - enumerate the first result of replaceAll +//2-priceAfterOneYear.replaceAll("," ,"")) in line 5 +//4-number(...) in line 5 - enumerate the second result of replaceAll +//5-console.log(..) - line 9 + // 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? +// the error is : a syntax error coming from the missing comma in line 5 between the arguments + + // c) Identify all the lines that are variable reassignment statements +// const priceDifference = carPrice - priceAfterOneYear; Line 7 +// const percentageChange = (priceDifference / carPrice) * 100; Line 8 // d) Identify all the lines that are variable declarations +// carPrice = Number(carPrice.replaceAll(",", "")); Line 4 +// priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", "")); Line 5 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression? +// the number function convert the enumerate a string to a number and the method replaceAll replace ever comma with a space +// the purpose is to clean the value so that it can be converted to a proper number using Number(). + diff --git a/Sprint-1/3-mandatory-interpret/2-time-format.js b/Sprint-1/3-mandatory-interpret/2-time-format.js index 47d239558..b993fcd03 100644 --- a/Sprint-1/3-mandatory-interpret/2-time-format.js +++ b/Sprint-1/3-mandatory-interpret/2-time-format.js @@ -1,4 +1,5 @@ -const movieLength = 8784; // length of movie in seconds + +const movieLength = -8789; // length of movie in seconds const remainingSeconds = movieLength % 60; const totalMinutes = (movieLength - remainingSeconds) / 60; @@ -12,14 +13,29 @@ 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 5 variable declarations // b) How many function calls are there? +// There are 4 function calls in line 9 and 10 // c) Using documentation, explain what the expression movieLength % 60 represents // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators +// % is a modulo operator that return the remainder of a multiplied number // d) Interpret line 4, what does the expression assigned to totalMinutes mean? +// movieLength subtract the left over seconds from the total seconds(movieLength) to get a number that is divisible by 60 +// when dividing by 60 would convert the remaining seconds into whole minutes which ensures there is no decimal in totalMinutes + // e) What do you think the variable result represents? Can you think of a better name for this variable? +// results present length of movie formatted as Hours:Minutes:Seconds and a better name could be movieDuration + // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer + +// whole positive value: for the 8789 seconds the formatted duration would be fine 2:26:29 and the code would be working as expected +// under 60 seconds: 59 seconds would assign the hours and minutes both as 0s resulting 0:0:59 instead of the normal formatted way 00:00:59 but still correct +// zero value: the formatted duration would also be correct 0:0:0 even though it is an unusual value it still show that it can handle it +// Negative value: for the -8789 seconds would give us an output of -2:-26:-29 which is not a valid format and doesn't make any sense +// the logic breaks where we need to give the user a message to enter a valid number +// diff --git a/Sprint-1/3-mandatory-interpret/3-to-pounds.js b/Sprint-1/3-mandatory-interpret/3-to-pounds.js index 60c9ace69..08fad0d5f 100644 --- a/Sprint-1/3-mandatory-interpret/3-to-pounds.js +++ b/Sprint-1/3-mandatory-interpret/3-to-pounds.js @@ -23,5 +23,23 @@ console.log(`£${pounds}.${pence}`); // You need to do a step-by-step breakdown of each line in this program // Try and describe the purpose / rationale behind each step + // To begin, we can start with // 1. const penceString = "399p": initialises a string variable with the value "399p" + +// 2. const penceStringWithoutTrailingP = penceString.substring(0,penceString.length - 1); reassigned a new value +// using the method substring starting form the index 0 ="3" and ending with -1 exclusively meaning doesn't include 'p' +// resulting with a numeric part of the price which is '399' + +//3.const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0"); +// ensure the number in a 3 digits format by adding zeros minding the consistency of the formatting. + +//4.const pounds = paddedPenceNumberString.substring(0,paddedPenceNumberString.length - 2); +//extracts everything except the last two number to form the pound portion of the price + +//5.const pence = paddedPenceNumberString.substring(paddedPenceNumberString.length - 2).padEnd(2, "0"); +//extracts the last two digits to form the pence portion of the price and the padEnd method ensure the number in a two digits format consistent + +//6.console.log(`£${pounds}.${pence}`); +//Combines everything into the final formatted price string. Result: £3.99 +//basically the program will take the string "399p" and print out a string of "£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 e7dd5feaf..f635079c6 100644 --- a/Sprint-1/4-stretch-explore/chrome.md +++ b/Sprint-1/4-stretch-explore/chrome.md @@ -11,8 +11,11 @@ In the Chrome console, invoke the function `alert` with an input string of `"Hello world!"`; What effect does calling the `alert` function have? +It shows a message on the middle top of the page with a sting "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`? +It shows a pop up box message with the sting "What is your name?" as an input in the middle top of the page +What is the return value of `prompt`? +it returns the text the user enters or an empty string if enter nothing in case cancel would return null diff --git a/Sprint-1/4-stretch-explore/objects.md b/Sprint-1/4-stretch-explore/objects.md index 0216dee56..0da365f99 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? +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` Answer the following questions: What does `console` store? +The console stores the history of messages your code prints while it runs What does the syntax `console.log` or `console.assert` mean? In particular, what does the `.` mean? +"." is called a dot notation where we can get access sth that belong to an object and the syntax means that we are accessing the methods that belong to the object console. \ No newline at end of file