London | 26-ITP-May | Tomislav Dukez | Sprint 1 | Coursework

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

@@ -4,3 +4,9 @@ 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 updating the value of the count variable. 
+    The = operator is an assignment operator that takes the value on the right side (count + 1) 
+    and assigns it to the variable on the left side (count). 
+    This means that the current value of count is increased by 1, and then that new value is stored back into the count variable.
+    The same effect could be achieved with the shorthand operator `count += 1`, or even better with `count++` which increments the value of count by 1.
+*/

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
-
+console.log(initials);

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

@@ -17,7 +17,8 @@ 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("."));
+console.log(`The dir part of ${filePath} is ${dir}`);
+console.log(`The ext part of ${filePath} is ${ext}`);
 // https://www.google.com/search?q=slice+mdn

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

@@ -7,3 +7,6 @@ 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
+console.log(num);
+
+// num is a random integer between the minimum and maximum values (inclusive), that is, a value between 1 and 100 (inclusive).

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

@@ -1,4 +1,6 @@
 // trying to create an age variable and then reassign the value by 1
 
-const age = 33;
+let age = 33;
 age = age + 1;
+
+console.log(age);

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

@@ -1,5 +1,5 @@
 // Currently trying to print the string "I was born in Bolton" but it isn't working...
 // what's the error ?
 
+const cityOfBirth = "Bolton"; // cityOfBirth wasn't declared and given a value before the console.log
 console.log(`I was born in ${cityOfBirth}`);
-const cityOfBirth = "Bolton";

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

@@ -1,9 +1,16 @@
 const cardNumber = 4533787178994213;
-const last4Digits = cardNumber.slice(-4);
+const last4Digits = Number(String(cardNumber).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
+
+// Slice method can be used on strings and arrays, not on numbers.
+// The error message is telling that slice is not a function, but this happens because number don't have a slice method.
+// I have used String(cardNumber) to convert the number to a string, so that the slice method can be used on it.
+// Then the 4 digit string is converted back to a number with Number(string) to match the expected type.

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

@@ -1,2 +1,10 @@
-const 12HourClockTime = "8:53pm";
-const 24hourClockTime = "20:53";
+const twelveHourClockTime = "8:53pm";
+const twentyFourHourClockTime = "20:53";
+
+console.log(twelveHourClockTime);
+console.log(twentyFourHourClockTime);
+
+// The code wasn't working because of the original variable names that were starting with a number.
+// So, I renamed the variables:
+// 12HourClockTime to twelveHourClockTime
+// 24HourClockTime to twentyFourHourClockTime

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 +12,17 @@ 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 2 function calls in this file:
+// Lines 4 and 5 - replaceAll function call
 
 // 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?
+// Line 5 had an error because there was a missing comma between "," and "" in replaceAll function call. - SyntaxError
 
 // c) Identify all the lines that are variable reassignment statements
+// Lines 4  and 5 are variable reassignment statements for carPrice and priceAfterOneYear.
 
 // d) Identify all the lines that are variable declarations
-
+// Lines 1, 2, 7 and 8 are variable declarations for carPrice, priceAfterOneYear, priceDifference and percentageChange.
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+// replaceAll function is used to replace all the occurrences of a character in a string.
+// The expression Number() is converting the string carPrice, that was pruned of the comma, to a number.

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

@@ -9,17 +9,46 @@ const totalHours = (totalMinutes - remainingMinutes) / 60;
 const result = `${totalHours}:${remainingMinutes}:${remainingSeconds}`;
 console.log(result);
 
+// testing different cases
+function movieLengthToDuration(movieLength) {
+  const remainingSeconds = movieLength % 60;
+  const totalMinutes = (movieLength - remainingSeconds) / 60;
+
+  const remainingMinutes = totalMinutes % 60;
+  const totalHours = (totalMinutes - remainingMinutes) / 60;
+
+  const result = `${totalHours}:${remainingMinutes}:${remainingSeconds}`;
+  return result;
+}
+
+console.log(movieLengthToDuration(0));
+console.log(movieLengthToDuration(59));
+console.log(movieLengthToDuration(10000));
+console.log(movieLengthToDuration(-100));
+console.log(movieLengthToDuration(200.4));
 // 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.
 
 // b) How many function calls are there?
+// There are no function calls.
 
 // c) Using documentation, explain what the expression movieLength % 60 represents
 // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators
+// This expression is a remainder left after the movieLength value is divided by 60 and represents the value of reimaining seconds.
+// % - is a remainder operator, or modulo operator.
 
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
+// From the movieLength variable, we subtract the remainingSeconds value from the movieLength value.
+// We then divide the result by 60 to get the totalMinutes value, that is the number of whole minutes in the movie duration.
 
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
+// The variable result represents the final result of the movie duration in the format of H:M:S.
+// The better name fort this variable could be  movieDuration.
 
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+// There are a couple of edge cases that this code will not work for:
+// if movieLength is less than 0, which is not a valid duration, the code will give calculation, but it will not return a valid result.
+// if movieLength is a decimal number, the code will give calculation, but the format will not be followed.
+//

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

@@ -25,3 +25,8 @@ 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): removes the trailing "p" from the string
+// 3. const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0"): pads the string with leading zeros to make it 3 characters long
+// 4. const pounds = paddedPenceNumberString.substring(0, paddedPenceNumberString.length - 2): extracts the first two characters from the padded string
+// 5. const pence = paddedPenceNumberString.substring(paddedPenceNumberString.length - 2).padEnd(2, "0"): extracts the last two characters from the padded string and pads them with leading zeros to make them 2 characters long
+// 6. console.log(`£${pounds}.${pence}`);: this line prints the result to the console

Sprint-1/4-stretch-explore/chrome.md

@@ -12,7 +12,12 @@ invoke the function `alert` with an input string of `"Hello world!"`;
 
 What effect does calling the `alert` function have?
 
+- It activates a pop-up window with the text "Hello world!" with "OK" as the button text. The execution is paued until the user clicks the "OK" button.
+
 Now try invoking the function `prompt` with a string input of `"What is your name?"` - store the return value of your call to `prompt` in an variable called `myName`.
 
 What effect does calling the `prompt` function have?
-What is the return value of `prompt`?
+
+- It activates a pop-up window with the text "What is your name?" with input field and "OK" and "Cancel" buttons. The execution is paused until the user enters a value and clicks the "OK" button.
+  What is the return value of `prompt`?
+- The return value of the prompt function is the value entered by the user in the input field.

Sprint-1/4-stretch-explore/objects.md

@@ -5,12 +5,47 @@ In this activity, we'll explore some additional concepts that you'll encounter i
 Open the Chrome devtools Console, type in `console.log` and then hit enter
 
 What output do you get?
+function log()
+length: 0
+name: "log"
+<prototype>: function ()
 
 Now enter just `console` in the Console, what output do you get back?
-
+Console { assert: assert(), clear: clear(), count: count(), countReset: countReset(), debug: debug(), error: overrideMethod(n), info: info(), log: log(), table: table(), trace: overrideMethod(n), … }
+assert: function assert()
+clear: function clear()
+count: function count()
+countReset: function countReset()
+debug: function debug()
+dir: function dir()
+dirxml: function dirxml()
+error: function overrideMethod(n)
+exception: function exception()
+group: function group()
+groupCollapsed: function groupCollapsed()
+groupEnd: function groupEnd()
+info: function info()
+log: function log()
+profile: function profile()
+profileEnd: function profileEnd()
+table: function table()
+time: function time()
+timeEnd: function timeEnd()
+timeLog: function timeLog()
+timeStamp: function timeStamp()
+trace: function overrideMethod(n)
+warn: function overrideMethod(n)
+Symbol(Symbol.toStringTag): "console"
+<prototype>: Object { }
 Try also entering `typeof console`
 
-Answer the following questions:
+- "object"
+  Answer the following questions:
 
 What does `console` store?
-What does the syntax `console.log` or `console.assert` mean? In particular, what does the `.` mean?
+
+- console stores an object that contains a collection of methods (functions) used for debugging and logging information to the browser's console.
+  What does the syntax `console.log` or `console.assert` mean? In particular, what does the `.` mean?
+- `console.log` is a method of the `console` object that logs a message to the console.
+- `console.assert` is a method of the `console` object that checks if a condition is true, and if not, throws an error.
+- The `.` in `console.log` and `console.assert` is a property access operator. It means that `console` is an object, and `log` and `assert` are its properties or methods.