London | 26-ITP-SEPT | Carol Nassuna | Sprint 2 | Coursework

Sprint-2/1-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
+
+//Answer: The = means assignment. The value of count is 0 but it increments by 1

Sprint-2/1-key-exercises/2-initials.js

@@ -2,9 +2,9 @@ const firstName = "Creola";
 const middleName = "Katherine";
 const 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.
 
-const initials = ``;
+const initials = firstName[0] + middleName[0] + lastName[0];
+console.log(initials);
 
 // https://www.google.com/search?q=get+first+character+of+string+mdn

Sprint-2/1-key-exercises/3-paths.js

@@ -17,7 +17,10 @@ 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
+console.log(`The dir part of ${filePath} is ${dir}`);
+console.log(`The ext part of ${base} is ${ext}`);
+
+// https://www.google.com/search?q=slice+mdn

Sprint-2/1-key-exercises/4-random.js

@@ -2,8 +2,20 @@ const minimum = 1;
 const maximum = 100;
 
 const num = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum;
+// (0.68 * 100 ) + 1
+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
+
+// Answer: For calculations i utilised BODMAS formula solving numbers in brackets first, multiplication, subtraction and addition
+// I used 0.68 for math.floor(random number) + 1
+// Sum = 69
+// 1.num is a random whole number from 1 to 100.
+// 2.start by (maximum-minimum +1) which the output is 100
+// 3.math.random()*100 returns random number between 0 and 100. Any random number less that 1 can be selected then multiplied by 100
+// 4.math.floor() gives out the largest integer which is less than or equal to the given number which is a decimal
+// The output is displayed in console log
+// 5. + minimum adds 1. So the range 0 to 99 becomes 1 to 100.

Sprint-2/2-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?
+// 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 commented out the lines. The computer removes commented lines from code compilation

Sprint-2/2-mandatory-errors/1.js

@@ -1,4 +1,9 @@
 // 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);
+
+// The TypeError: Assignment to constant variable implies we are trying to reassign the variable twice.
+// This case, I have used let instead in order to allow the variable to be reused.

Sprint-2/2-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 error is ReferenceError: Cannot access 'cityOfBirth' before initialization
+// Answer: I switched the order by declaring the const first before calling /printing

Sprint-2/2-mandatory-errors/3.js

@@ -1,9 +1,15 @@
 const cardNumber = 4533787178994213;
-const last4Digits = cardNumber.slice(-4);
+const last4Digits = String(cardNumber).slice(-4);
+console.log(last4Digits);
 
 // 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
 // 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
+
+//Prediction was the code would run successfully without error although with the wrong results due to absence of syntax errors in the file
+// Error returned: TypeError: cardNumber.slice is not a function
+// Lesson learnt here; slice method is only available for strings or arrays not numbers
+// I used String() on line 2 to turn the number into a string

Sprint-2/2-mandatory-errors/4.js

@@ -1,2 +1,7 @@
-const 12HourClockTime = "8:53pm";
-const 24hourClockTime = "20:53";
+const twelveHourClockTime = "8:53pm";
+const twentyFourHourClockTime = "20:53";
+console.log(twelveHourClockTime);
+console.log(twentyFourHourClockTime);
+
+// Error - SyntaxError: Invalid or unexpected token
+// lesson learnt - variables cannot start with a number

Sprint-2/3-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 +12,21 @@ 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
-
+// 5
+// * number() and .replaceAll() in line 4
+// * number() and .replaceAll()in line 5
+// console.log() is on line 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?
-
+//b) error = SyntaxError: missing ) after argument list
+// (",", ",")); - added , between quoted values
+// The error was coming from line 5 due to a missing comma in the replaceAll() method
 // c) Identify all the lines that are variable reassignment statements
-
+//carPrice = Number(carPrice.replaceAll(",", ""));
+//priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ","));
 // d) Identify all the lines that are variable declarations
-
+//let carPrice = "10,000";
+//let priceAfterOneYear = "8,543";
+//const priceDifference = carPrice - priceAfterOneYear;
+//const percentageChange = (priceDifference / carPrice) * 100;
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+// e) cleans the amount format by removing characters such as , and leaving only number

Sprint-2/3-mandatory-interpret/2-time-format.js

@@ -12,14 +12,21 @@ 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 variables
 
 // b) How many function calls are there?
-
+// 1 (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
+// 24 seconds
 
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
+// totalMinutes is assigned a value of the result from (movieLength - remainingSeconds) / 60;
+//it means changing the value that was in second into minute by dividing it 60 - making it a whole number
 
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
+// I think its the total movie length with a timer. Based on research it appears to be template literal variable as it mixes static text with dynamic data. Sorry I don't fully understand this bit yet
+// It represents the movieDuration
 
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+//any number greater than zero returns a valid positive hour, minute or seconds result. Changing the length to 0 returns 0:0:0. Any negative length returns negative values

Sprint-2/3-mandatory-interpret/3-to-pounds.js

@@ -2,13 +2,13 @@ const penceString = "399p";
 
 const penceStringWithoutTrailingP = penceString.substring(
   0,
-  penceString.length - 1
+  penceString.length - 1,
 );
 
 const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");
 const pounds = paddedPenceNumberString.substring(
   0,
-  paddedPenceNumberString.length - 2
+  paddedPenceNumberString.length - 2,
 );
 
 const pence = paddedPenceNumberString
@@ -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. P will be dropped
+// 3. const paddedPenceNumberString - ensures the figure is 3 characters to taking us back to 399
+// 4 const pounds - removes 2 characters from the amount = 3
+// 5. substring(paddedPenceNumberString.length - 2) takes the last 2 characters of 399 which is 99. padEnd(2, "0") adds zeros for strings shorter than 2 characters. In this case, 99 is already 2 characters so nothing is added.
+// 6. console displays the figures in pounds and pence = 3.99

Sprint-2/4-stretch-explore/chrome.md

@@ -12,4 +12,4 @@ What effect does calling the `alert` function have?
 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`?
+What is the return value of `prompt`?.

Sprint-2/4-stretch-explore/objects.md

@@ -13,4 +13,4 @@ Try also entering `typeof console`
 Answer the following questions:
 
 What does `console` store?
-What does the syntax `console.log` or `console.assert` mean? In particular, what does the `.` mean?
+What does the syntax `console.log` or `console.assert` mean? In particular, what does the `.` mean?.