JavaScript code interpretation

Author: fromonda

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

@@ -12,11 +12,28 @@ 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 this file. They occur on the following 3 lines:
+// carPrice = Number(carPrice.replaceAll(",", ""));
+// priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ""));
+// console.log(`The percentage change is ${percentageChange}`);
 
 // 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 code contains one syntax error on the following line:
+// priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ""));
+// A comma is missing between the arguments inside replaceAll(). It should be:
+// priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", ""));
 
 // c) Identify all the lines that are variable reassignment statements
+// The lines that are variable reassignment statements are as follows:
+// carPrice = Number(carPrice.replaceAll(",", ""));
+// priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ""));
 
 // d) Identify all the lines that are variable declarations
+// The lines that contain variable declarations are as follows:
+// 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?
+// It removes the comma from the car price string and converts it into a number so it can be used in calculations.

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?
+// Six variables are declared in this program.
 
 // b) How many function calls are there?
+// In this program, the only function call is:
+// 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 expression movieLength % 60 yields the remaining seconds after converting the total seconds into full minutes.
 
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
+// It calculates the total number of full minutes in the movie length.
 
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
+// It represents the movie length formatted as a time string in hours:minutes:seconds format.
+// A better name for this variable could be const formattedTime.
 
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+// The code does not produce the desired output for all possible values of movieLength.
+// It does not work correctly for decimal values.

Sprint-1/3-mandatory-interpret/3-to-pounds.js

@@ -25,3 +25,13 @@ console.log(`£${pounds}.${pence}`);
 
 // 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):
+// removes the trailing "p" from the string, leaving only the numeric part ("399")
+// 3. const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0"):
+// ensures that the numeric string has at least three characters by adding leading zeros if necessary
+// 4. const pounds = paddedPenceNumberString.substring(0, paddedPenceNumberString.length - 2):
+// extracts all the digits except the last two, representing the number of pounds
+// 5. const pence = paddedPenceNumberString.substring(paddedPenceNumberString.length - 2).padEnd(2, "0"):
+// extracts the last two digits representing the pence
+// 6. console.log(`£${pounds}.${pence}`):
+// yields the final price in pounds and pence using the format £pounds.pence