diff --git a/Sprint-1/1-key-exercises/1-count.js b/Sprint-1/1-key-exercises/1-count.js index 117bcb2b6..2b6707df6 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 + //Answer : Line 3 increases the value of count by 1 and then reassigns it to count with new 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..cb28610ae 100644 --- a/Sprint-1/1-key-exercises/2-initials.js +++ b/Sprint-1/1-key-exercises/2-initials.js @@ -5,7 +5,9 @@ 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); + +console.log(initials); + -// 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..98ab371c3 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(".")); // 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..5266f9499 100644 --- a/Sprint-1/1-key-exercises/4-random.js +++ b/Sprint-1/1-key-exercises/4-random.js @@ -3,7 +3,18 @@ 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? + + //Answer : num represents a random integer 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 + + //1- Math.floor(...) rounds the number down to the nearest whole number, giving an integer from 0 to 99. + //2- Math.random() generates a decimal number between 0 and 1. + //3- Math.random() * (maximum - minimum + 1) make sure that decimal to a range from 0 up to (maximum - minimum + 1). + + + diff --git a/Sprint-1/2-mandatory-errors/0.js b/Sprint-1/2-mandatory-errors/0.js index cf6c5039f..9b86743a2 100644 --- a/Sprint-1/2-mandatory-errors/0.js +++ b/Sprint-1/2-mandatory-errors/0.js @@ -1,2 +1,4 @@ -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? + +// Answer : we put them in comment syntax \ 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..851b821dc 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; +console.log(age); \ 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..7cbc5b9a4 100644 --- a/Sprint-1/2-mandatory-errors/2.js +++ b/Sprint-1/2-mandatory-errors/2.js @@ -1,5 +1,9 @@ // Currently trying to print the string "I was born in Bolton" but it isn't working... -// what's the error ? +// what's the error ? +// const was declared after using it , we have to declare a variable first and then use it. + +// console.log(`I was born in ${cityOfBirth}`); +// const cityOfBirth = "Bolton"; -console.log(`I was born in ${cityOfBirth}`); const cityOfBirth = "Bolton"; +console.log(`I was born in ${cityOfBirth}`); \ 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..098580033 100644 --- a/Sprint-1/2-mandatory-errors/3.js +++ b/Sprint-1/2-mandatory-errors/3.js @@ -1,5 +1,6 @@ -const cardNumber = 4533787178994213; -const last4Digits = cardNumber.slice(-4); +// const cardNumber = 4533787178994213; +// const last4Digits = cardNumber.slice(-4); + // The last4Digits variable should store the last 4 digits of cardNumber // However, the code isn't working @@ -7,3 +8,7 @@ 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 + +const cardNumber = 4533787178994213; +const last4Digits = cardNumber.toString().slice(-4); +console.log(last4Digits); \ 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..965cde854 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 12HourClockTime = "20:53"; +// const 24hourClockTime = "08:53"; + + +//identifiers cannot start with a number in Javascript. \ 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..6c0d441af 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 +11,17 @@ 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 : + //Answer : 5 functions // 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? + //Answe: line 5 . we need a comma (,) between the arguments.puting (,) between ("," "") -// c) Identify all the lines that are variable reassignment statements +// c) Identify all the lines that are variable reassignment statements : + //Answe: line 4 and line 5 // d) Identify all the lines that are variable declarations + //Answer: line 1, 2, 6, 7 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression? + //Answer: Remove formatting commas from the price string and then convert it to a number so we can do arithmetic. diff --git a/Sprint-1/3-mandatory-interpret/2-time-format.js b/Sprint-1/3-mandatory-interpret/2-time-format.js index 47d239558..2fa15ef77 100644 --- a/Sprint-1/3-mandatory-interpret/2-time-format.js +++ b/Sprint-1/3-mandatory-interpret/2-time-format.js @@ -11,15 +11,27 @@ 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? +// a) How many variable declarations are there in this program? + //Answer: 6 + // b) How many function calls are there? + //Answer: 1 + // c) Using documentation, explain what the expression movieLength % 60 represents // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators + //Answer: % is the modulus operator and movieLength % 60 gives the remainder when movieLength is divided by 60. + // d) Interpret line 4, what does the expression assigned to totalMinutes mean? + //Answer: movieLength - remainingSeconds → subtracts the leftover seconds, leaving only the total number of seconds that make full minutes + //Dividing by 60 converts those seconds to total whole minutes So totalMinutes is the total minutes in the movie ignoring leftover seconds + // e) What do you think the variable result represents? Can you think of a better name for this variable? + //Answer: result is a string representing the movie length in HH:MM:SS format and better name MovieTimeFormat + // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer + //Answer: It just works for positive integer diff --git a/Sprint-1/3-mandatory-interpret/3-to-pounds.js b/Sprint-1/3-mandatory-interpret/3-to-pounds.js index 60c9ace69..31d097366 100644 --- a/Sprint-1/3-mandatory-interpret/3-to-pounds.js +++ b/Sprint-1/3-mandatory-interpret/3-to-pounds.js @@ -1,21 +1,29 @@ const penceString = "399p"; +//Initialize a string variable representing the price in pence with a trailing "p" characte const penceStringWithoutTrailingP = penceString.substring( 0, penceString.length - 1 ); +//Remove the "p" so we can manipulate the numeric value const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0"); +// Pad the string to at least 3 digits so Makes it easier to separate pounds and pence consistently. + const pounds = paddedPenceNumberString.substring( 0, paddedPenceNumberString.length - 2 ); +//Extract the pounds part so This gives the whole pounds part of the price. const pence = paddedPenceNumberString .substring(paddedPenceNumberString.length - 2) .padEnd(2, "0"); + //Extract the pence part so Ensures pence is always 2 digits. + console.log(`£${pounds}.${pence}`); +//Combine pounds and pence into a formatted string // This program takes a string representing a price in pence // The program then builds up a string representing the price in pounds diff --git a/Sprint-1/4-stretch-explore/chrome.md b/Sprint-1/4-stretch-explore/chrome.md index e7dd5feaf..6cd7d4680 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? + answer : Displays a pop-up dialog box with a message and an OK button; execution pauses until OK is clicked. 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? +Displays a pop-up dialog box with a message and a text input field; execution pauses until OK or Cancel is clicked. + What is the return value of `prompt`? +Returns the string entered by the user if OK is clicked, or null if Cancel is clicked. diff --git a/Sprint-1/4-stretch-explore/objects.md b/Sprint-1/4-stretch-explore/objects.md index 0216dee56..288c01cd8 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? +Answer : It shows ƒ log() { [native code] }. Now enter just `console` in the Console, what output do you get back? +Answer : It shows console {debug: ƒ, error: ƒ, info: ƒ, log: ƒ, warn: ƒ, …} Try also entering `typeof console` +Answer:object Answer the following questions: What does `console` store? +Answer:console is an object that stores methods for logging and debugging, like log, error, warn, assert, etc. + What does the syntax `console.log` or `console.assert` mean? In particular, what does the `.` mean? +Answer: The . accesses a property or method of the console object.