Sheffield | 26-Jan-ITP| Mona-Eltantawy | Sprint 1 | Coursework/ Sprint1

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

@@ -4,3 +4,8 @@ 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 and incerment operation that increasing the value of the count variable by adding 1 to its current value.
+ The = opperator is an assignment opperator that assigns the result of the expression on the right (count+1) to the varibale on the left (count). 
+ so, if count was 0 befor line 3 is excuted it will be 1 after line 3 is excuted.
+  And if it was 1 it will be 2 after line 3 is excuted. 

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

@@ -5,7 +5,7 @@ let 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.
 
-let initials = ``;
+let initials = firstName[0] + middleName[0] + lastName[0];
 
 // https://www.google.com/search?q=get+first+character+of+string+mdn
 

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

@@ -16,8 +16,7 @@ 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 lastDotIndex = filePath.lastIndexOf(".");
+const ext = filePath.slice(lastDotIndex); 
 
-const dir = ;
-const ext = ;
-
-// https://www.google.com/search?q=slice+mdn
+// https://www.google.com/search?q=slice+mdn

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

@@ -7,3 +7,5 @@ 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
+
+num represents a random integer between the minimum and maximum values (inclusive).

Sprint-1/2-mandatory-errors/0.js

@@ -1,2 +1,4 @@
 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?
+We don't want the computer to run these 2 lines - how can we solve this problem?
+
+comment it out using // at the start of each line, or use /* at the start and */ at the end to comment out a block of code. 

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

@@ -2,3 +2,10 @@
 
 const age = 33;
 age = age + 1;
+in this code we are trying to reassign the value of age variable by adding 1 to ageTrack. 
+However, this will result in an error because the age variable is diclared as a constant using the const keyword. 
+And in javascript, a variable decalred with const cannot be readdigned a new value afteer it has been intialised ,
+ so if we want to reassign the vlaue we have to use let instead. 
+ let age = 33;
+ age = age +1;
+

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

@@ -1,5 +1,6 @@
 // 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}`);
+
+Because the const varibale is decalred after it is used in the console={.log} statement and it should be decalred befor to be executed. 

Sprint-1/2-mandatory-errors/3.js

@@ -1,9 +1,16 @@
 const cardNumber = 4533787178994213;
-const last4Digits = cardNumber.slice(-4);
+const last4Digits = cardNumber .toString().slice(-4);
+console.log(last4Digits);
 
 // 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 exepected first that the .slice negative value (-4) will count from the beganning and drob of the first four Numbers. 
+When I run the code the error was that the cardNumber is not a function, 
+so I thought that I might need to turn the code into a function, 
+but when I checked an AI toolbar it showed that .slice is a methode that is used for string and array ,
+ so the card number should turned into a string by add .tostring after the card number and then use the .slice method to get the last 4 last4Digits.

Sprint-1/2-mandatory-errors/4.js

@@ -1,2 +1,4 @@
 const 12HourClockTime = "20:53";
-const 24hourClockTime = "08:53";
+const 24hourClockTime = "08:53";
+
+In javascript variabl names should not start with a Number. 

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 +12,35 @@ 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
+there are 4 function calls in this File, they are in the following lines:
+line 1: carPrice.replaceAll(",", "")
+line 2: priceAfterOneYear.replaceAll(",", "")
+line 3: Number(carPrice.replaceAll(",", ""))
+line 4: Number(priceAfterOneYear.replaceAll(",", ""))
 
 // 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?
 
 // c) Identify all the lines that are variable reassignment statements
+there are 4 variables reassignment statements in this file, in the following lines:
+line 1 = carPrice =
+line 2 = priceAfterOneYear =
+line 3 = carPrice = Number(carPrice.replaceAll(",", ""))
+line 4 = priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", ""))
+
+
+
 
 // d) Identify all the lines that are variable declarations
+there are 2 variable declarations in this file , in :
+line 1 : let carPrice = 
+line 2 : let priceFterOneYear =
+
 
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+
+the expression `Number(carPrice.replaceAll(",", ""))` is doing the following:
+1. `carPrice.replaceAll(",", "")` removes all commas from the string value of `carPrice`.
+2. `Number(...)` converts the resulting string (which no longer contains commas) into a number.
+
+This is necessary because the original `carPrice` variable is a string with commas (e.g., "10,000"), and JavaScript cannot perform mathematical operations on strings with commas.
+ The purpose of this expression is to convert the formatted price string into a numeric value that can be used in calculations.

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

@@ -12,14 +12,36 @@ 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 6 variable declarations in this programe they are in the following lines:
+
+const movieLength = 8784; // length of movie in seconds
+
+const remainingSeconds = movieLength % 60;
+const totalMinutes = (movieLength - remainingSeconds) / 60;
+
+const remainingMinutes = totalMinutes % 60;
+const totalHours = (totalMinutes - remainingMinutes) / 60;
+
+const result = `${totalHours}:${remainingMinutes}:${remainingSeconds}`;
 
 // b) How many function calls are there?
+there is 1 function call in this program and it is in the following line: 
+
+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
+https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators
+
+The expression `movieLength % 60` calculates the remainder when `movieLength` is divided by 60. 
+In this context, it gives the number of seconds that remain after converting the total seconds into minutes and hours.
 
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
+The expression assigned to `totalMinutes` calculates the total number of minutes in `movieLength` 
+by subtracting the remaining seconds and dividing by 60.
+
 
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
+variable result represents the formatted remaining movielength time in hours, minutes, and seconds (HH:MM:SS). we can change the varible name to formattedTime or formattedMovieLength to make it more descriptive.
 
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+yes this code will work for all values of movieLength asa long as it is a non- negative integers.

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

@@ -24,4 +24,24 @@ console.log(`£${pounds}.${pence}`);
 // 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"
+1. const penceString = "399p": initialises a string variable with the value "399p"
+2. const penceStringWithoutTrailingP = penceString.substring(
+  0, penceString.length - 1);
+This line removes the trailing "p" from the pence string, leaving just the numeric value "399".
+
+3. const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");
+This line pads the numeric string with leading zeros to ensure it is at least 3 characters long, resulting in "0399".
+
+4. const pounds = paddedPenceNumberString.substring(
+  0,
+  paddedPenceNumberString.length - 2
+);
+This line extracts the pounds part by taking all characters except the last two (which represent pence), resulting in "03".
+
+5. const pence = paddedPenceNumberString
+  .substring(paddedPenceNumberString.length - 2)
+  .padEnd(2, "0");
+This line extracts the last two characters (representing pence) and ensures they are exactly two digits long by padding with trailing zeros if necessary, resulting in "99".
+however the padEnd is not necessary in this case because the substring will alwayes return 2 characters since we have already padded the string to be at least 3 characters long in the previouse Step.
+6. console.log(`£${pounds}.${pence}`);
+This line logs the formatted price in pounds and pence, e.g., £03.99.