mandatory interpret done

Author: RaihanSharif

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

@@ -12,11 +12,19 @@ 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
+// Total: 5
+// 2 in line 4, 2 in line 5
+// 1 in 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?
+// Error in line 5, missing comma after first arguement in replaceAll.
 
 // c) Identify all the lines that are variable reassignment statements
+// Lines 4, and 5
 
 // d) Identify all the lines that are variable declarations
+// Lines 1, 2, 7, 8
 
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+// replaceAll function returns a new string with all commas removed, so that it is a valid input for Number.
+// Number takes an input and converts it to a number.

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

@@ -1,4 +1,4 @@
-const movieLength = 8784; // length of movie in seconds
+const movieLength = -5784; // length of movie in seconds
 
 const remainingSeconds = movieLength % 60;
 const totalMinutes = (movieLength - remainingSeconds) / 60;
@@ -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?
+// 6
 
 // b) How many function calls are there?
+// 1
 
 // c) Using documentation, explain what the expression movieLength % 60 represents
 // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators
+// % is the remainder operator in JavaScript. The expression represents the remainder after dividing
+// movieLength by 60, in this case: 24.
 
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
+// The total length of the movie in minutes, after taking away the fractional part (the 24 seconds).
 
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
+// The exact runtime of the movie, converted from seconds into hours, minutes and seconds format.
 
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+// It works with all positive values of movieLength. For negative values, it produces negative hours, minutes, and seconds.
+// This is due to the fact that % is a remainder operator, not a true modulo operator. It always takes the sign of the divided.
+// So if you divide a negative number, the remainder will be negative.

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

@@ -1,4 +1,4 @@
-const penceString = "399p";
+const penceString = "9p";
 
 const penceStringWithoutTrailingP = penceString.substring(
   0,
@@ -25,3 +25,22 @@ console.log(`£${pounds}.${pence}`);
 
 // To begin, we can start with
 // 1. const penceString = "399p": initialises a string variable with the value "399p"
+
+// 3. const penceStringWithoutTrailingP = penceString.substring(0, penceString.length - 1);
+// removes the trailing p so that there's a clean number format to work with.
+
+// 8. const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");
+// pad the start so that there's always a character (0) in the pound's place, and the 10th and 100th place of the
+// fractional part (pence). E.g. for 9 pence, the pre-padded number would be "9", by padding it with 0, you get
+// 009, which can easily be formatted as £0.09.
+
+// 9. const pounds = paddedPenceNumberString.substring(0, paddedPenceNumberString.length - 2);
+// final two characters will always represent pence, be it "09" for 9 pence, or "90" for 90 pence
+// so the pound part will be anything preceding those two characters.
+
+// 14. const pence = paddedPenceNumberString.substring(paddedPenceNumberString.length - 2).padEnd(2, "0");
+// I guess, this is trying to ensure that pence always amounts to at least 2 digits, but it is unnecessary
+// as you're always taking the last two digits and padStart in line 8 ensures that the string always has at least 3 characters.
+
+// 18. console.log(`£${pounds}.${pence}`);
+// this is just adding a pound symbol at the start and joining the pound and pence parts captured earlier with a dot.