interpreting the programs

Author: Ebrahim-Moqbel

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;
@@ -12,11 +12,27 @@ 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
+//1-carPrice.replaceAll(",", "") in line 4
+//3-number(...) in line 4 - enumerate the first result of replaceAll
+//2-priceAfterOneYear.replaceAll("," ,"")) in line 5
+//4-number(...) in line 5 - enumerate the second result of replaceAll
+//5-console.log(..) - line 9
+
 
 // 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 : a syntax error coming from the missing comma in line 5 between the arguments 
+
+
 
 // c) Identify all the lines that are variable reassignment statements
+// const priceDifference = carPrice - priceAfterOneYear;  Line 7
+// const percentageChange = (priceDifference / carPrice) * 100;  Line 8
 
 // d) Identify all the lines that are variable declarations
+// carPrice = Number(carPrice.replaceAll(",", ""));  Line 4
+// priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", ""));  Line 5
 
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+// the number function convert the enumerate a string to a number and the method replaceAll replace ever comma with a space
+// the purpose is to clean the value so that it can be converted to a proper number using Number().
+

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

@@ -1,4 +1,5 @@
-const movieLength = 8784; // length of movie in seconds
+
+const movieLength = -8789; // length of movie in seconds
 
 const remainingSeconds = movieLength % 60;
 const totalMinutes = (movieLength - remainingSeconds) / 60;
@@ -12,14 +13,29 @@ 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?
+// There are 5 variable declarations
 
 // b) How many function calls are there?
+// There are 4 function calls  in line 9 and 10
 
 // c) Using documentation, explain what the expression movieLength % 60 represents
 // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators
+// % is a modulo operator that return the remainder of a multiplied number 
 
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
+// movieLength subtract the left over seconds from the total seconds(movieLength) to get a number that is divisible by 60
+// when dividing by 60 would convert the remaining seconds into whole minutes which ensures there is no decimal in totalMinutes
+
 
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
+// results present length of movie formatted as Hours:Minutes:Seconds and a better name could be movieDuration
+
 
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+
+// whole positive value: for the 8789 seconds the formatted duration would be fine 2:26:29 and the code would be working as expected 
+// under 60 seconds: 59 seconds would assign the hours and minutes both as 0s resulting 0:0:59 instead of the normal formatted way 00:00:59 but still correct 
+// zero value: the formatted duration would also be correct 0:0:0 even though it is an unusual value it still show that it can handle it 
+// Negative value: for the -8789 seconds would give us an output of -2:-26:-29 which is not a valid format and doesn't make any sense
+// the logic breaks where we need to give the user a message to enter a valid number 
+// 

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

@@ -23,5 +23,23 @@ 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
 
+
 // 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); reassigned a new value 
+// using the method substring starting form the index 0 ="3" and ending with -1 exclusively meaning doesn't include 'p' 
+// resulting with a numeric part of the price which is '399'
+
+//3.const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");
+// ensure the number in a 3 digits format by adding zeros minding the consistency of the formatting.
+
+//4.const pounds = paddedPenceNumberString.substring(0,paddedPenceNumberString.length - 2);
+//extracts everything except the last two number to form the pound portion of the price
+
+//5.const pence = paddedPenceNumberString.substring(paddedPenceNumberString.length - 2).padEnd(2, "0");
+//extracts the last two digits to form the pence portion of the price and the padEnd method ensure the number in a two digits format consistent 
+
+//6.console.log(`£${pounds}.${pence}`);
+//Combines everything into the final formatted price string. Result: £3.99
+//basically the program will take the string "399p" and print out a string of "£3.99"