Complete 3-mandatory-interpret

Author: jakr-s

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 +13,31 @@ 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
 
+// carPrice.replaceAll(",", "") (line 4)
+// Number(carPrice.replaceAll(",", "")) (line 4)
+// priceAfterOneYear.replaceAll(",", "") (line 5)
+// Number(priceAfterOneYear.replaceAll(",", "")) (line 5)
+// console.log(`The percentage change is ${percentageChange}`) (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?
 
+// Syntax error - Arguments need to be separated by a comma
+
 // c) Identify all the lines that are variable reassignment statements
 
+// carPrice = Number(carPrice.replaceAll(",", "")) (line 4)
+// priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", "")) (line 5)
+
 // d) Identify all the lines that are variable declarations
 
+// let carPrice = "10,000" (line 1)
+// let priceAfterOneYear = "8,543" (line 2)
+// const priceDifference = carPrice - priceAfterOneYear (line 7)
+// const percentageChange = (priceDifference / carPrice) * 100 (line 8)
+
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+
+// (carPrice.replaceAll(",", "")) takes the string stored in the carPrice variable ("10,000") and removes all instances of commas (",")
+// Without this, the result of Number(carPrice) would be NaN (Not a Number)
+
+// Number(...) then takes the edited string ("10000") and converts it to a number (10000) so that numerical operations can be performed on this value

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

@@ -13,13 +13,30 @@ console.log(result);
 
 // 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
 
+// It gives the remainder left over when one number is divided by another
+
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
 
+// Its subtracts the remainder from the movieLength so that it can be divided into a whole number
+
+// (movieLength - remainingSeconds) / 60
+// 8760 / 60 = 146
+
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
 
+// The variable represents the movie length in seconds converted to a (HH:MM:SS) format
+// A better variable name would be 'formattedTime'
+
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+
+// No, this code will not work for all values of movieLength
+// In edge cases where movieLength is assigned a value of a negative number or string, the output will not make sense

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

@@ -1,20 +1,27 @@
+// 1. initialises a string variable with the value "399p"
 const penceString = "399p";
 
+// 2. removes the trailing 'p' character
 const penceStringWithoutTrailingP = penceString.substring(
   0,
   penceString.length - 1
 );
 
+// 3. pads the numeric string with leading zeros so it is at least 3 digits
 const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");
+
+// 4. extracts the pound part by taking all but the last two digits
 const pounds = paddedPenceNumberString.substring(
   0,
   paddedPenceNumberString.length - 2
 );
 
+// 5. extracts the pence part by taking the last two digits, and pads with trailing zeroes if needed
 const pence = paddedPenceNumberString
   .substring(paddedPenceNumberString.length - 2)
   .padEnd(2, "0");
 
+// 6. formats and prints the result as a pounds and pence string
 console.log(`£${pounds}.${pence}`);
 
 // This program takes a string representing a price in pence