Birmingham | 25-ITP-Sep | Joy Opachavalit | Sprint 1 | coursework/sprint-3

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

@@ -12,11 +12,29 @@ 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 function calls 
+//Line 4: carPrice.replaceAll(",", "")
+//Line 4: Number(...) – wraps the above
+//Line 5: priceAfterOneYear.replaceAll(",", "") ✅ But this line has a syntax error (we’ll get to it)
+//Line 5: Number(...) – wraps the above
+//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?
+//syntax error! On line 5, there's a missing comma in the replaceAll method. 
+//correct code should be
+//priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", ""));
 
 // 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";
 
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+// This expression converts a string with commas into a number that can be used for mathematical calculations:
+// 1. carPrice.replaceAll(",", "") - removes all commas from the string "10,000" → "10000"
+// 2. Number(...) - converts the cleaned string "10000" into the number 10000
+// Purpose: Strings with commas cannot be used in math operations, so we need to clean and convert them to numbers first

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

@@ -12,14 +12,33 @@ 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 variable declarations
+//Line 1: movieLength
+//Line 3: remainingSeconds
+//Line 4: totalMinutes
+//Line 6: remainingMinutes
+//Line 7: totalHours
+//Line 9: result        
 
 // b) How many function calls are there?
+// 1 function call
+//Line 10: 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. It returns the remainder left over when one operand is divided by a second operand.
+// In this case, movieLength % 60 calculates the number of seconds remaining after dividing the total movie length by 60 (the number of seconds in a minute).
+// For example, if movieLength is 8784 seconds, then 8784 % 60 equals 24, meaning there are 24 seconds left over after accounting for full minutes.
 
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
+// The expression (movieLength - remainingSeconds) / 60 calculates the total number of minutes in the movie by first removing the remaining seconds and then dividing by 60 (the number of seconds in a minute).
 
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
+// The variable result represents the formatted string output of the total hours, remaining minutes, and remaining seconds of the movie.
+// A better name for this variable could be formattedMovieLength.
 
 // 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 non-negative integer values of movieLength. It correctly calculates hours, minutes, and seconds for any length of time.
+// However, if movieLength is negative or not an integer, the results may not make sense in the context of a movie length.
+// For example, if movieLength is negative, the calculations for hours, minutes, and seconds will yield negative values, which are not valid for a movie duration.
+// Additionally, if movieLength is a non-integer (e.g., a float), the calculations will still work, but the interpretation of the result may be less clear since movie lengths are typically represented as whole seconds.      

Sprint-1/3-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. const penceStringWithoutTrailingP = penceString.substring(0, penceString.length - 1): removes the trailing 'p' from the string to isolate the numeric part
+// 3. const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0"): pads the numeric string with leading zeros to ensure it is at least 3 digits long
+// 4. const pounds = paddedPenceNumberString.substring(0, paddedPenceNumberString.length - 2): extracts the pounds portion from the padded string
+// 5. const pence = paddedPenceNumberString.substring(paddedPenceNumberString.length - 2).padEnd(2, "0"): extracts the pence portion and ensures it is 2 digits long
+// 6. console.log(`£${pounds}.${pence}`): outputs the final formatted string representing the price in pounds