London | 26-ITP-Sep | Ebrahim Moqbel | Sprint 2 | Coursework

Sprint-2/1-key-exercises/1-count.js

@@ -4,3 +4,5 @@ count = count + 1;
 
 // Line 1 is a variable declaration, creating the count variable with an initial value of 0
 // Describe what line 3 is doing, in particular focus on what = is doing
+
+// Line 3 is an increment  where = is an assignment operator and in there we are adding value of 1 to the count variable

Sprint-2/1-key-exercises/2-initials.js

@@ -5,6 +5,7 @@ const lastName = "Johnson";
 // Declare a variable called initials that stores the first character of each string.
 // This should produce the string "CKJ", but you must not write the characters C, K, or J in the code of your solution.
 
-const initials = ``;
+const initials = `${firstName.charAt(0)}${middleName.charAt(0)}${lastName.charAt(0)}`;
 
+console.log(initials);
 // https://www.google.com/search?q=get+first+character+of+string+mdn

Sprint-2/1-key-exercises/3-paths.js

@@ -17,7 +17,7 @@ console.log(`The base part of ${filePath} is ${base}`);
 // Create a variable to store the dir part of the filePath variable
 // Create a variable to store the ext part of the variable
 
-const dir = ;
-const ext = ;
+const dir = filePath.slice(0, lastSlashIndex);
+const ext = filePath.slice(filePath.lastIndexOf("."));
 
-// https://www.google.com/search?q=slice+mdn
+// https://www.google.com/search?q=slice+mdn

Sprint-2/1-key-exercises/4-random.js

@@ -7,3 +7,13 @@ const num = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum;
 // Try breaking down the expression and using documentation to explain what it means
 // It will help to think about the order in which expressions are evaluated
 // Try logging the value of num and running the program several times to build an idea of what the program is doing
+
+// math.floor round down to the nearest whole number e.g Math.floor(4.4) or Math.floor(4.8) will return 4
+// math.ceil round up to the nearest whole number e.g Math.ceil(4.8) and Math.ceil(4.4) will return 5
+// (maximum - minimum + 1) provide a range of generated random number
+// num is a random whole number [1,100]
+
+console.log(Math.floor(4.8));
+console.log(Math.floor(4.4));
+console.log(Math.ceil(4.8));
+console.log(Math.ceil(4.4));

Sprint-2/2-mandatory-errors/0.js

@@ -1,2 +1,2 @@
-This is just an instruction for the first activity - but it is just for human consumption
-We don't want the computer to run these 2 lines - how can we solve this problem?
+// This is just an instruction for the first activity - but it is just for human consumption
+// We don't want the computer to run these 2 lines - how can we solve this problem?

Sprint-2/2-mandatory-errors/1.js

@@ -1,4 +1,10 @@
 // trying to create an age variable and then reassign the value by 1
 
-const age = 33;
+let age = 33;
 age = age + 1;
+
+/* 
+The error thrown was a TypeError indicating assignment to constant variable and this happen when 
+we declare a variable with const and try to give it a new value
+
+*/

Sprint-2/2-mandatory-errors/2.js

@@ -1,5 +1,7 @@
 // Currently trying to print the string "I was born in Bolton" but it isn't working...
 // what's the error ?
 
-console.log(`I was born in ${cityOfBirth}`);
 const cityOfBirth = "Bolton";
+console.log(`I was born in ${cityOfBirth}`);
+
+// the error is that cityOfBirth variable declared after the logging command

Sprint-2/2-mandatory-errors/3.js

@@ -1,9 +1,13 @@
 const cardNumber = 4533787178994213;
-const last4Digits = cardNumber.slice(-4);
+// const last4Digits = cardNumber.slice(-4);
 
 // The last4Digits variable should store the last 4 digits of cardNumber
 // However, the code isn't working
 // Before running the code, make and explain a prediction about why the code won't work
 // Then run the code and see what error it gives.
 // Consider: Why does it give this error? Is this what I predicted? If not, what's different?
 // Then try updating the expression last4Digits is assigned to, in order to get the correct value
+
+// I predicted the last four digits bit it has to be a string in order to use the method slice and that explain why it wasn't working
+const last4Digits = cardNumber.toString().slice(-4);
+console.log(last4Digits);

Sprint-2/2-mandatory-errors/4.js

@@ -1,2 +1,6 @@
-const 12HourClockTime = "8:53pm";
-const 24hourClockTime = "20:53";
+const twelveHourClockTime = "8:53pm";
+const twentyFourHourClockTime = "20:53";
+// The old version of the variables return a SyntaxError pointing that there is Invalid or unexpected token
+// For naming the variables we need to use the naming convention which involved not leading the variable name with a number
+
+console.log(twelveClockTime);

Sprint-2/3-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 +12,29 @@ 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
+//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
+/* 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?
+/* the number function convert the enumerate a string to a number and the method replaceAll replace ever comma with empty string 
+ the purpose is to clean the value so that it can be converted to a proper number using Number().
+ */

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

@@ -12,14 +12,26 @@ 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?
+//A--> There are 6 variable declarations
 
 // b) How many function calls are there?
+//A--> There are 1 function call  in line 10 which is ===> console.log(result);
 
-// c) Using documentation, explain what the expression movieLength % 60 represents
+// c) Usings documentation, explain what the expression movieLength % 60 represents
 // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators
+//A--> % is a modulo operator that return the remainder which is the leftover of a division of two numbers
 
 // 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?
+//A--> results present length of movie formatted as Hours:Minutes:Seconds and a better name could be fromatedMovieDuration
 
 // 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 8784 seconds the formatted duration would be fine 2:26:24 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 -8784 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-2/3-mandatory-interpret/3-to-pounds.js

@@ -2,13 +2,13 @@ const penceString = "399p";
 
 const penceStringWithoutTrailingP = penceString.substring(
   0,
-  penceString.length - 1
+  penceString.length - 1,
 );
 
 const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");
 const pounds = paddedPenceNumberString.substring(
   0,
-  paddedPenceNumberString.length - 2
+  paddedPenceNumberString.length - 2,
 );
 
 const pence = paddedPenceNumberString
@@ -25,3 +25,20 @@ 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); 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"