London | 26-ITP-Sep | Mahdi Rafiei | Sprint 2 | Coursework

Sprint-2/1-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
+//adds 1 to the value of count and then = operator stores that value in count variable

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

@@ -5,6 +5,6 @@ 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];
 
 // https://www.google.com/search?q=get+first+character+of+string+mdn

Sprint-2/1-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 = filePath.slice(filePath.lastIndexOf(".") + 1);
 
-// https://www.google.com/search?q=slice+mdn
+// https://www.google.com/search?q=slice+mdn

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

@@ -7,3 +7,9 @@ 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
+
+//num represents a random whole number between 1 and 100
+// Math.random() produces a random decimal from 0 up to 1 .
+// Math.random() * 100 produces a decimal from 0 up to 100.
+// Math.floor() rounds the number down to a whole number, giving 0–99.
+// +minimum (+1) shifts that range to 1–100.

Sprint-2/2-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?
+// 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?

Sprint-2/2-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;

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

@@ -1,5 +1,5 @@
 // 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}`);
+

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

@@ -1,9 +1,11 @@
 const cardNumber = 4533787178994213;
-const last4Digits = cardNumber.slice(-4);
+const last4Digits = String(cardNumber).slice(-4);
 
 // 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
+
+// The .slice() method works on strings, but numbers don't have a .slice() method

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

@@ -1,2 +1,2 @@
-const 12HourClockTime = "8:53pm";
-const 24hourClockTime = "20:53";
+const clockTime12Hour = "8:53pm";
+const clockTime24Hour = "20:53";

Sprint-2/3-mandatory-interpret/1-percentage-change.js

@@ -12,11 +12,26 @@ 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 are 5 function calls in the code:
 
 // 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 original code has an error here:
+//line 5 : It should be: replaceAll(",", "")
+// There is also another problem: carPrice and priceAfterOneYear
+// are declared with const, so they cannot be reassigned.
+// They should be declared with let if we want to reassign them.
 
 // 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
+// const carPrice = "10,000";
+// const 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?
+// First, replaceAll(",", "") removes the comma from "10,000", producing the string "10000".
+// Then Number() converts the string "10000" into the number 10000.
+// This is necessary so that we can perform mathematical calculations with the price.

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?
-
+// There are 7 variable declarations: movieLength, remainingSeconds, totalMinutes, remainingMinutes, totalHours, result
 // b) How many function calls are there?
-
+// There is 1 function call: console.log(result)
 // c) Using documentation, explain what the expression movieLength % 60 represents
 // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators
+// The % operator is the remainder operator. movieLength % 60 finds the remainder after dividing movieLength by 60.
 
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
-
+// Calculate the total number of complete minutes.
+// First, subtract the remaining seconds from the movie length,
+// leaving a number that can be divided exactly by 60.
+// Then divide by 60 to convert seconds into minutes.
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
-
+// result represents the movie length converted from seconds into hours, minutes and seconds.
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+// The code works correctly for positive whole numbers of seconds.
+// However, it may not give a useful result for negative numbers,
+// decimals, or values that are not numbers.

Sprint-2/3-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. penceString.substring(0, penceString.length - 1): Removes the final character ("p") from the string.
+// 3. padStart(3, "0"): Makes sure the number contains at least 3 characters. If it has fewer than 3 characters, zeros are added to the beginning.
+// 4. substring(0, paddedPenceNumberString.length - 2): Gets everything except the final two characters. The final two characters represent the pence.
+// 5. substring(paddedPenceNumberString.length - 2): Gets the final two characters of the string.
+// 6. console.log(...): Combines the pounds and pence into a price format.