LONDON |ITP-MAY-2025| KHILOLARUSTAMOVA | Coursework/sprint1

Sprint-1/1-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
+// The = operator updates the value of count by assigning it a new value so count is not =0 anymore it is = to 1
+

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

@@ -3,9 +3,9 @@ let middleName = "Katherine";
 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 = ``;
+// This should produce the string "CKJ", but you must not write the characters C, K, or J in the code of your solution
 
 // https://www.google.com/search?q=get+first+character+of+string+mdn
 
+//Get the first character of each name using [0]
+let initials = firstName[0] + middleName[0] + lastName[0];

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

@@ -10,14 +10,15 @@
 // (All spaces in the "" line should be ignored. They are purely for formatting.)
 
 const filePath = "/Users/mitch/cyf/Module-JS1/week-1/interpret/file.txt";
-const lastSlashIndex = filePath.lastIndexOf("/");
-const base = filePath.slice(lastSlashIndex + 1);
+const lastSlashIndex = filePath.lastIndexOf("/"); // 55
+const base = filePath.slice(lastSlashIndex + 1); // file.txt
 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 dotIndex=filePath.lastIndexOf("."); 
+const ext = base.slice(dotIndex+1);
 
 // https://www.google.com/search?q=slice+mdn

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

@@ -3,6 +3,38 @@ const maximum = 100;
 
 const num = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum;
 
+
+Math.random()
+
+This gives you a random decimal number between 0 (inclusive) and 1 (not including 1).
+
+Example output: 0.3, 0.89, 0.01, etc.
+
+(maximum - minimum + 1)
+
+This calculates how many possible numbers there are between minimum and maximum, including both.
+
+In this case: 100 - 1 + 1 = 100 possible numbers.
+
+Math.random() * (maximum - minimum + 1)
+
+Multiplies the random decimal by 100. This gives a number between 0 and just under 100.
+
+Example: If Math.random() gives 0.66, then 0.66 * 100 = 66.
+
+Math.floor(...)
+
+Rounds the result down to the nearest whole number.
+
+So 66.8 becomes 67.
+
++ minimum
+
+This shifts the range from 0–99 to 1–100.
+
+So if Math.floor(...) gave 67, then adding 1 gives 68.
+
+
 // In this exercise, you will need to work out what num represents?
 // 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

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

@@ -1,2 +1,16 @@
 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?
+Single-line comment
+Use // at the beginning of the line:
+
+
+// This is just an instruction for the first activity
+// We don't want the computer to run these 2 lines
+Multi-line comment
+Use /* */ for multiple lines:
+
+/*
+This is just an instruction for the first activity.
+We don't want the computer to run these 2 lines.
+*/
+

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

@@ -2,3 +2,8 @@
 
 const age = 33;
 age = age + 1;
+// to be able to reassign the value we need to use let instead of const because the value of const can not be changed after it is set. 
+let age = 33;
+age = age + 1;
+
+

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

@@ -3,3 +3,9 @@
 
 console.log(`I was born in ${cityOfBirth}`);
 const cityOfBirth = "Bolton";
+
+// this code has order problem. const and let has to have it`s value has to be declared before you use it.
+// to fix it we will change the order of the code.
+
+const cityOfBirth = "Bolton";
+console.log(`I was born in ${cityOfBirth}`);

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

@@ -7,3 +7,10 @@ const last4Digits = cardNumber.slice(-4);
 // 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
+
+
+This will give an error because cardNumber is a number, and .slice() is a method that only works on strings or arrays — not numbers.
+for this to work we need to change the card number to a string
+
+const cardNumber = "4533787178994213"; // use quotes to make it a string
+const last4Digits = cardNumber.slice(-4);

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

@@ -1,2 +1,13 @@
 const 12HourClockTime = "20:53";
-const 24hourClockTime = "08:53";
+const 24hourClockTime = "08:53";
+
+//Variable names in JavaScript cannot start with a number.
+// so we have to change 12 to twelve and 24 to twentyFour 
+
+const twelveHourClockTime = "08:53";   // 12-hour time (8:53 AM)
+const twentyFourHourClockTime = "20:53"; // 24-hour time (8:53 PM)
+
+// we can also put it this way:
+
+const clock12 = "08:53";
+const clock24 = "20:53";

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

@@ -20,3 +20,58 @@ console.log(`The percentage change is ${percentageChange}`);
 // d) Identify all the lines that are variable declarations
 
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+
+
+//answers
+
+// a) in total we have 5 function calls here:
+Line 4: carPrice.replaceAll(",", "")
+
+Line 4: Number(...)
+
+Line 5: priceAfterOneYear.replaceAll("," "") — this line has an error (missing comma)
+
+Line 5: Number(...)
+
+Line 8: console.log(...)
+
+
+//b) on line 5 there is a missing coma between arguments. (",""") should be (",","")
+
+//c) The variable reassignment statements are:
+
+ Line 4: carPrice = Number(carPrice.replaceAll(",", ""));
+
+Line 5: priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ""));
+
+Line 8: console.log(`The percentage change is ${percentageChange}`);
+
+//d) The variable declarations are:
+
+// Line 1: let carPrice = "10,000";
+
+// Line 2: let priceAfterOneYear = "8,543";
+
+// Line 6: const priceDifference = carPrice - priceAfterOneYear;
+
+// Line 7: const percentageChange = (priceDifference / carPrice) * 100;
+
+// e) The expression
+
+carPrice.replaceAll(",", "") removes all commas from the string (e.g., turns "10,000" into "10000").
+
+Number(...) converts the resulting string "10000" into a number type 10000.
+
+Purpose: To convert a formatted string number with commas into an actual number so you can do arithmetic on it.
+
+
+
+
+
+
+
+
+
+
+
+

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?
+1) const movieLength = 8784; // length of movie in seconds
+
+2) const remainingSeconds = movieLength % 60;
+3) const totalMinutes = (movieLength - remainingSeconds) / 60;
+
+4) const remainingMinutes = totalMinutes % 60;
+5) const totalHours = (totalMinutes - remainingMinutes) / 60;
+
+6)const result = `${totalHours}:${remainingMinutes}:${remainingSeconds}`;
 
 // b) How many function calls are there?
+1)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_Ope
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
+This line is finding the number of seconds left over after dividing the total movie length by 60 seconds (1 minute).
 
-// e) What do you think the variable result represents? Can you think of a better name for this variable?
+movieLength is the total time of a movie in seconds.
 
+60 is the number of seconds in a minute.
+
+% is the modulus operator — it gives you the remainder after division.
+
+
+// e) What do you think the variable result represents? Can you think of a better name for this variable?
+It represents the movie length formatted as hours, minutes, and seconds.
+✅ A better name would be:
+formattedTime
+durationString
+movieTimeFormatted
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+yes it works for different numbers