diff --git a/Sprint-1/1-key-exercises/1-count.js b/Sprint-1/1-key-exercises/1-count.js index 117bcb2b6..64ffc4f16 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 reassigns the variable count by taking its current value, adding 1 to it, and storing the new value back into count. The = operator assigns the value on the right to the variable on the left. diff --git a/Sprint-1/1-key-exercises/2-initials.js b/Sprint-1/1-key-exercises/2-initials.js index 47561f617..ec8d2aa6a 100644 --- a/Sprint-1/1-key-exercises/2-initials.js +++ b/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[0] + middleName[0] + lastName[0]; // https://www.google.com/search?q=get+first+character+of+string+mdn +console.log(initials); \ 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..a1d89ed5f 100644 --- a/Sprint-1/1-key-exercises/3-paths.js +++ b/Sprint-1/1-key-exercises/3-paths.js @@ -17,7 +17,9 @@ 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 lastDotIndex = base.lastIndexOf("."); +const ext = base.slice(lastDotIndex + 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..3abe93106 100644 --- a/Sprint-1/1-key-exercises/4-random.js +++ b/Sprint-1/1-key-exercises/4-random.js @@ -3,7 +3,15 @@ const maximum = 100; const num = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum; +console.log(num); // 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 + +// Math.random https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/random +// Math.floor https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/floor +// mdn order of operations javascript https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Operator_precedence + + +// It generates a random whole number between 1 and 100 \ 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..6a7a7f690 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..cf826388d 100644 --- a/Sprint-1/2-mandatory-errors/1.js +++ b/Sprint-1/2-mandatory-errors/1.js @@ -1,4 +1,10 @@ // trying to create an age variable and then reassign the value by 1 -const age = 33; +let age = 33; age = age + 1; + +console.log(age); + +// Another way to write this code... +// let age = 33; +// age++; diff --git a/Sprint-1/2-mandatory-errors/2.js b/Sprint-1/2-mandatory-errors/2.js index e09b89831..533bcfb52 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}`); + + +// The variable was declared after console.log \ 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..e71d6f3b0 100644 --- a/Sprint-1/2-mandatory-errors/3.js +++ b/Sprint-1/2-mandatory-errors/3.js @@ -1,5 +1,7 @@ const cardNumber = 4533787178994213; -const last4Digits = cardNumber.slice(-4); +const last4Digits = cardNumber.toString().slice(-4); + +console.log(last4Digits); // The last4Digits variable should store the last 4 digits of cardNumber // However, the code isn't working @@ -7,3 +9,5 @@ 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 + +// This won't work because cardNumbers is a number, and numbers don't have the .slice() 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..29f7f43fe 100644 --- a/Sprint-1/2-mandatory-errors/4.js +++ b/Sprint-1/2-mandatory-errors/4.js @@ -1,2 +1,5 @@ -const 12HourClockTime = "20:53"; -const 24hourClockTime = "08:53"; \ No newline at end of file +const twelveHourClockTime = "20:53"; +const twentyFourHourClockTime = "08:53"; + +console.log(twelveHourClockTime); +console.log(twentyFourHourClockTime); \ 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..329662d47 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 +12,16 @@ 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 is 5 function calls, anything that has () afterwards is a function. // 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 added a a comma , here --> (priceAfterOneYear.replaceAll(",", "")); as this was missing, I seen this as soon as i opened this exercise. // c) Identify all the lines that are variable reassignment statements +// Lines 4 and 5 are reassignments, carPrice was declared with let and priceAfterOneYear was already declared with let. // d) Identify all the lines that are variable declarations +// There is 4 declarations in total, theres where all varibales crated using let,const and var. (lines 1,2,7,8) // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression? +// breaking it down this part, carPrice.replaceAll(",", "") removes all commas from the string. Next step is this Number("10000"), this converts the string into a number. \ 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..4332801ff 100644 --- a/Sprint-1/3-mandatory-interpret/2-time-format.js +++ b/Sprint-1/3-mandatory-interpret/2-time-format.js @@ -12,14 +12,23 @@ 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 is 6 variable declarations in this program. // b) How many function calls are there? +// There is 1 function call. console.log(); // c) Using documentation, explain what the expression movieLength % 60 represents // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators +// This means divide movieLength by 60 and return what is left over. + // d) Interpret line 4, what does the expression assigned to totalMinutes mean? +// Subtract the leftover seconds and divide by 60 so this calculates the total number of full minutes in the movie. // e) What do you think the variable result represents? Can you think of a better name for this variable? +// This builds a formatted string that looks like hours:minutes:seconds so the movie duration converted in time format (HH:MM:SS) +// Result is quite vague a better variable name could be formattedTime // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer +// This works for positive whole numbers and any length in seconds. +// It doesn't work handling negative numbers properly. diff --git a/Sprint-1/3-mandatory-interpret/3-to-pounds.js b/Sprint-1/3-mandatory-interpret/3-to-pounds.js index 60c9ace69..c604fc026 100644 --- a/Sprint-1/3-mandatory-interpret/3-to-pounds.js +++ b/Sprint-1/3-mandatory-interpret/3-to-pounds.js @@ -25,3 +25,17 @@ console.log(`£${pounds}.${pence}`); // To begin, we can start with // 1. const penceString = "399p": initialises a string variable with the value "399p" +// 2. penceString.length gives the length of "399p" -> 4, length -1 = 3, substring(0,3) takes characters from idex 0 up to (but not including) index 3 +// 3. padStart(3, "0") ensures the string is at least 3 characters long. +// 4. const pounds = paddedPenceNumberString.substring( +// 0, +// paddedPenceNumberString.length - 2 +// ); +// What this does: it takes everything except the last 2 digits. Because: The last 2 digits represent pence and everything before that represents pounds. +// 5. substring(length - 2) --> takes the last 2 digits, .padEnd(2, "0") ensures it is always 2 digits. +// 6. console.log() --> builds a formatted currency string £3.99 + +// This program is doing overall, removing the "p", +// ensuring there are at least 3 digits, +// splitting the number into pounds and pence, +// finally formatting it into a proper currency 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..651877588 100644 --- a/Sprint-1/4-stretch-explore/chrome.md +++ b/Sprint-1/4-stretch-explore/chrome.md @@ -16,3 +16,8 @@ Now try invoking the function `prompt` with a string input of `"What is your nam What effect does calling the `prompt` function have? What is the return value of `prompt`? + +// The returned value of prompt --> The string I typed or null if I press cancel. +I typed Alasdair and when I called myName it was stored inside that variiable called myName. + +let myName = prompt("What is your name?"); \ 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..301387ce4 100644 --- a/Sprint-1/4-stretch-explore/objects.md +++ b/Sprint-1/4-stretch-explore/objects.md @@ -14,3 +14,6 @@ Answer the following questions: What does `console` store? What does the syntax `console.log` or `console.assert` mean? In particular, what does the `.` mean? + + +Typing console.log shows a function definition (e.g. ƒ log() { [native code] }). This means console.log is a built-in function provided by the browser. \ No newline at end of file