Manchester | 26-ITP-May | Samreen Amjad | Sprint 2 | Coursework

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

@@ -3,4 +3,4 @@ let count = 0;
 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 = takes the result of count + 1 and saves it back into the count variable, replacing the old value.

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

@@ -5,7 +5,8 @@ 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]}`;
 
+console.log(initials); 
 // https://www.google.com/search?q=get+first+character+of+string+mdn
 

Sprint-1/1-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 = base.slice(base.lastIndexOf("."));
 
 // https://www.google.com/search?q=slice+mdn

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

@@ -3,7 +3,13 @@ const maximum = 100;
 
 const num = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum;
 
-// 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
-// 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 represents a random integer between 1 and 100 (inclusive).
+
+// 1. Math.random() generates a random decimal in [0, 1)
+// 2. (maximum - minimum + 1) = 100, which means Math.random() * 100 gives a decimal in [0, 100)
+// 3. Math.floor(...) rounds down to an integer in [0, 99]
+// 4. Adding minimum (1) shifts the range to [1, 100]
+// Which means num is a random whole number from 1 to 100.

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?
+// 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?
+
+// Solution is making the instruction to a comment by using two slashes.

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

@@ -1,4 +1,7 @@
 // trying to create an age variable and then reassign the value by 1
 
-const age = 33;
+let age = 33;
 age = age + 1;
+
+// The error is assignment to constant variable.
+// const variables cannot be reassigned. I can fix this by using let instead.

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

@@ -1,5 +1,8 @@
 // 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}`);
+
+// console.log is meant to be at the bottom 

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

@@ -1,9 +1,22 @@
 const cardNumber = 4533787178994213;
-const last4Digits = cardNumber.slice(-4);
+const last4Digits = 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
+
+// I think the code will not work because cardNumber is a number, and .slice() only works with strings.
+
 // Then run the code and see what error it gives.
+
+//TypeError: cardNumber.slice is not a function
+
+
 // Consider: Why does it give this error? Is this what I predicted? If not, what's different?
+
+// The error happens because slice() cannot be used on a number. It only works on strings. Yes, this is what I predicted because I expected an error caused by trying to use slice() on a number. There is no difference between my prediction and the actual error.
+
+
 // Then try updating the expression last4Digits is assigned to, in order to get the correct value

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

@@ -1,2 +1,2 @@
-const 12HourClockTime = "8:53pm";
-const 24hourClockTime = "20:53";
+const twelveHourClockTime = "8:53pm";
+const twentyFourHourClockTime = "20:53";

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 +12,19 @@ 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
+//The function call are made five times
+//line  4, 5, 10
 
 // 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, A comma was missing between the arguments. Include a comma between the arguments to fix the error.
 
 // c) Identify all the lines that are variable reassignment statements
 
+//Lines 7 & 8
+
 // d) Identify all the lines that are variable declarations
 
+//Lines 1 & 2
+
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+//It first removes all commas from the string (e.g. "10,000" becomes "10000"), then converts the resulting string into a number using Number(). This allows the value to be used in mathematical calculations.

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

@@ -13,13 +13,26 @@ console.log(result);
 
 // a) How many variable declarations are there in this program?
 
+//6 variable declarations
+
+
 // b) How many function calls are there?
 
+//One function call - 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
 
+//The % (remainder) operator returns the remainder after dividing by 60. - 8784 % 60  this returns 24, which is the number of seconds left over after converting to whole minutes. 
+
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
 
+// It removes the leftover seconds from movieLength and then divides by 60 to calculate the total whole minutes.
+
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
 
+//formattedTime
+
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+
+//// No because it only works for whole numbers of seconds, but it won't format the time properly if the minutes or seconds are less than 10.

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

@@ -1,27 +1,32 @@
 const penceString = "399p";
 
+//It stores the price as a string in pence.
+
 const penceStringWithoutTrailingP = penceString.substring(
   0,
   penceString.length - 1
 );
 
+//Removes the "p" from the end of the string.
+
 const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");
+
+//Makes sure the string has at least 3 digits by adding leading zeros if needed. 
+
 const pounds = paddedPenceNumberString.substring(
   0,
   paddedPenceNumberString.length - 2
 );
 
+//Takes all the digits except the last two to get the pounds.
+
 const pence = paddedPenceNumberString
   .substring(paddedPenceNumberString.length - 2)
   .padEnd(2, "0");
 
-console.log(`£${pounds}.${pence}`);
+  // Takes the last two digits to get the pence.
 
-// This program takes a string representing a price in pence
-// The program then builds up a string representing the price in pounds
+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
+//Combines the pounds and pence into a currency format and prints it.
 
-// To begin, we can start with
-// 1. const penceString = "399p": initialises a string variable with the value "399p"

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

@@ -12,7 +12,14 @@ invoke the function `alert` with an input string of `"Hello world!"`;
 
 What effect does calling the `alert` function have?
 
+A pop up notification saying Hello World
+
 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?
+
+It brings up a input tab to enter an answer
+
 What is the return value of `prompt`?
+
+Tprompt returns the text that the user enters as a string if cancelled it would return null

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

@@ -6,11 +6,23 @@ Open the Chrome devtools Console, type in `console.log` and then hit enter
 
 What output do you get?
 
+undefined/ f log() native code
+
 Now enter just `console` in the Console, what output do you get back?
 
+It shows that console stores an object with many functions inside it.
+
 Try also entering `typeof console`
 
+object
+
 Answer the following questions:
 
-What does `console` store?
+What does `console` store
+
+Console stores an object that contains tools for displaying information in the browser console, for example console.log() this displays messages or console.error() this displays errors.
+
+
 What does the syntax `console.log` or `console.assert` mean? In particular, what does the `.` mean?
+
+The . is called the dot operator, it is used to access properties or methods inside an object. An example is console.log()

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

@@ -1,13 +1,12 @@
 // Predict and explain first...
-//  =============> write your prediction here
+//A) Error message - str has already been declared
 
 // call the function capitalise with a string input
 // interpret the error message and figure out why an error is occurring
 
 function capitalise(str) {
-  let str = `${str[0].toUpperCase()}${str.slice(1)}`;
-  return str;
+  let capitalisedStr = `${str[0].toUpperCase()}${str.slice(1)}`;
+  return capitalisedStr;
 }
 
-// =============> write your explanation here
-// =============> write your new code here
+console.log(capitalise("hello there"));

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

@@ -1,7 +1,9 @@
 // Predict and explain first...
 
 // Why will an error occur when this program runs?
-// =============> write your prediction here
+
+// The error happens because decimalNumber is declared twice.
+
 
 // Try playing computer with the example to work out what is going on
 
@@ -16,5 +18,17 @@ console.log(decimalNumber);
 
 // =============> write your explanation here
 
+//// The error happens because decimalNumber is already a parameter,
+// so it cannot be declared again using const.
+// Also, decimalNumber is inside the function, so it can't be
+// used outside the function with console.log().
+
 // Finally, correct the code to fix the problem
 // =============> write your new code here
+
+function convertToPercentage(decimalNumber) {
+  const percentage = `${decimalNumber * 100}%`;
+  return percentage;
+}
+
+console.log(convertToPercentage(0.5));

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

@@ -1,6 +1,9 @@
 
 // Predict and explain first BEFORE you run any code...
 
+// I think the code will give an error because 3 cannot be used
+// as a function parameter name. Parameters must be variable names.
+
 // this function should square any number but instead we're going to get an error
 
 // =============> write your prediction of the error here
@@ -11,10 +14,20 @@ function square(3) {
 
 // =============> write the error message here
 
+// SyntaxError: Unexpected number
+
 // =============> explain this error message here
+// The error means JavaScript found a number where it was
+// expecting a parameter name. Function parameters must be
+// identifiers like 'num', not values like 3.
 
 // Finally, correct the code to fix the problem
 
 // =============> write your new code here
 
+function square(num) {
+    return num * num;
+}
+
+console.log(square(3));
 

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

@@ -1,6 +1,9 @@
 // Predict and explain first...
 
-// =============> write your prediction here
+// I think the code will not give an error, but it will print
+// "The result of multiplying 10 and 32 is undefined" because
+// the function only logs the answer and does not return a value.
+
 
 function multiply(a, b) {
   console.log(a * b);
@@ -10,5 +13,14 @@ console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
 
 // =============> write your explanation here
 
+// The problem is that the multiply function uses console.log()
+// instead of returning the result. When a function does not
+// return anything, JavaScript gives it the value undefined.
+
 // Finally, correct the code to fix the problem
-//  =============> write your new code here
+
+function multiply(a, b) {
+  return a * b;
+}
+
+console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);

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

@@ -1,5 +1,10 @@
 // Predict and explain first...
-//  =============> write your prediction here
+
+// I think the code will not give an error, but it will print
+// "The sum of 10 and 32 is undefined" because the return statement
+// stops the function before a + b can run.
+
+
 
 function sum(a, b) {
   return;
@@ -9,5 +14,15 @@ function sum(a, b) {
 console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
 
 // =============> write your explanation here
+
+// The problem is that `return;` ends the function immediately.
+// The code after return will never be reached, so the function
+// does not return the sum of a and b. It returns undefined instead.
+
 // Finally, correct the code to fix the problem
-//  =============> write your new code here
+
+function sum(a, b) {
+  return a + b;
+}
+
+console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);