Mnadatory - interpret completed

Author: Dan2Clouted

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;
@@ -13,10 +13,25 @@ console.log(`The percentage change is ${percentageChange}`);
 
 // 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.
+// Line 4 : Number() and replaceAll()
+// Line 5 : Number() and replaceAll()
+// Line 10 : console.log()
+
 // 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 error is on line 5, where there is a syntax error in the replaceAll method call. The second argument is missing quotes.
+// To fix it, we need to add quotes around the empty string: replaceAll(",", "").
+
 // c) Identify all the lines that are variable reassignment statements
 
+// Line 4 and Line 5
+
 // d) Identify all the lines that are variable declarations
 
+// Line 1, 2, 7, 8.
+
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+
+// The expression is first calling the replaceAll method on the carPrice string to remove all commas. "10,000" ==> "10000".
+// Then it converts the resulting string into a number using the Number() function. "10000" ==> 10000.

Sprint-1/3-mandatory-interpret/2-time-format.js

@@ -1,10 +1,10 @@
 const movieLength = 8784; // length of movie in seconds
 
 const remainingSeconds = movieLength % 60;
-const totalMinutes = (movieLength - remainingSeconds) / 60;
+const totalMinutes = (movieLength - remainingSeconds) / 60; //146
 
-const remainingMinutes = totalMinutes % 60;
-const totalHours = (totalMinutes - remainingMinutes) / 60;
+const remainingMinutes = totalMinutes % 60; //26
+const totalHours = (totalMinutes - remainingMinutes) / 60; // 0
 
 const result = `${totalHours}:${remainingMinutes}:${remainingSeconds}`;
 console.log(result);
@@ -13,13 +13,28 @@ console.log(result);
 
 // a) How many variable declarations are there in this program?
 
+// There are 6 Variable declarations.
+
 // b) How many function calls are there?
 
+// There are 2 function calls. Console.log() and the template literal used.
+
 // c) Using documentation, explain what the expression movieLength % 60 represents
 // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators
 
+// movieLength % 60 gives the leftover seconds after converting seconds into whole minutes.
+
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
 
+//It gets the total minutes by removing the leftover seconds and converting the remaining seconds into minutes by dividing by 60.
+
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
 
+//remainingMinutes is the minutes part in an hours:minutes:seconds display
+// It can be named as minutesDisplay.
+
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+
+// The code will work for all positive integer values of MovieLength.
+// If movieLength is negative, the code will still run but it will give a negative time which doesn't make sense in this context.
+// If movieLength is not an integer, it will still run but it may give unexpected results due to the way the modulus operator works with non-integer values.

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

@@ -1,27 +1,32 @@
 const penceString = "399p";
 
+// This creates a string variable that represents a price in pence, with the letter p at the end.
+
 const penceStringWithoutTrailingP = penceString.substring(
   0,
   penceString.length - 1
 );
 
+// This takes the string from the start up to (but not including) the last character, so it removes the trailing "p" and leaves "399"
+
 const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");
+
+// This makes sure the pence number has at least 3 characters by adding zeros to the front if it’s too short (so "5" would become "005"), and "399" stays "399".
 const pounds = paddedPenceNumberString.substring(
   0,
   paddedPenceNumberString.length - 2
 );
 
+// This takes everything except the last 2 digits, which gives the pounds part (for "399" it becomes "3").
+
 const pence = paddedPenceNumberString
   .substring(paddedPenceNumberString.length - 2)
   .padEnd(2, "0");
 
-console.log(`£${pounds}.${pence}`);
+//This takes the last 2 digits to get the pence part (for "399" it becomes "99") and ensures it is always 2 digits long by padding with zeros on the right if needed.
 
-// This program takes a string representing a price in pence
-// The program then builds up a string representing the price in pounds
+console.log(`£${pounds}.${pence}`);
 
-// You need to do a step-by-step breakdown of each line in this program
-// Try and describe the purpose / rationale behind each step
+// This prints the final formatted price by inserting pounds and pence into a template string, producing £3.99.
 
-// To begin, we can start with
-// 1. const penceString = "399p": initialises a string variable with the value "399p"
+// This program takes a string representing a price in pence