Manchester| 25-ITP-Sep | Fithi Teklom| Sprint 2 | Coursework

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

@@ -17,7 +17,12 @@ 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 lastDotIndex = base.lastIndexOf(".");
+const ext = base.slice(lastDotIndex + 1);
+
+console.log("Directory path:", dir);
+console.log("File path:", base);
+console.log("File extension:", ext);
 
 // https://www.google.com/search?q=slice+mdn

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

@@ -3,7 +3,12 @@ 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 is a random integer between minimum and maximum, including both endpoints.
+// Math.random generates random decimal numbers between 0 and 1.
+// Math.floor() rounds a number down to the nearest integer.Example 12.8 is rounded to 12.
+//(maximum - minimum + 1)= (100 - 1 + 1)= 100.... So the expression becomes (Math.random()*100)
+//In the output I can see random numbers between 1 and 100.
+
+

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

@@ -1,2 +1,3 @@
-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?
+//we can simply comment it out by adding two slashes(//) at the begining of line 1 and line 2.

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;
+//let allows the variable to be reassigned later.
+//const is only for values that should never change.

Sprint-1/2-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}`);
+
+//declaration and initialization comes first always.

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

@@ -1,9 +1,8 @@
 const cardNumber = 4533787178994213;
-const last4Digits = cardNumber.slice(-4);
+const last4Digits = cardNumber.toString().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
+console.log(last4Digits);
+
+//I predicted the error which is type error. cardNumber is a number not a string.
+//.slice() only works on strings (or arrays).
+//Numbers in JavaScript do not have a slice method.

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

@@ -1,2 +1,2 @@
-const 12HourClockTime = "20:53";
-const 24hourClockTime = "08:53";
+const Hour12ClockTime = "20:53";
+const hour24ClockTime = "08:53";

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 +12,20 @@ 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 5 function calls. Number(), carPrice.replaceAll(),priceAfterOneYear.replaceAll(), console.log(),Number().
 
 // 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 at line 5. It is a Syntax error. A comma is expected in between the two strings.By adding , in between the stings.
 
 // c) Identify all the lines that are variable reassignment statements
+//carPrice = Number(carPrice.replaceAll(",", ""));
+//priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ,""));
 
 // d) Identify all the lines that are variable declarations
+//let carPrice = "10,000";
+//let priceAfterOneYear = "8,543";
+//const priceDifference = carPrice - priceAfterOneYear;
+//const percentageChange = (priceDifference / carPrice) * 100;
 
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+// It replaces the number to a clean string.

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

@@ -12,14 +12,21 @@ 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.
 
 // b) How many function calls are there?
+//1 function call.
 
 // c) Using documentation, explain what the expression movieLength % 60 represents
 // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators
+//Remainder assignment. Which means when 8784 seconds is divided by 60 it gives 146 with a remainder of 24.
 
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
+//movieLength - remainingSeconds removes the leftover seconds that don’t make up a full minute.
+//Dividing that by 60 converts the remaining seconds into whole minutes.
 
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
+//It represents movie duration. A better name can be formattedMovie.
 
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+// Mostly yes, but not good for fractional values, negative numbers and numbers less than 0, the leading 0 may not be displayed.

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

@@ -25,3 +25,9 @@ console.log(`£${pounds}.${pence}`);
 
 // To begin, we can start with
 // 1. const penceString = "399p": initialises a string variable with the value "399p"
+//3-6.substring(start, end) extracts characters from index start up to (but not including) end. Here we use penceString.length - 1 so we take every character except the final one — removing the trailing "p".
+//8. padStart(targetLength, padString) ensures the string has at least targetLength characters by adding padString at the start if needed. We padStart(3, "0") to guarantee the numeric string is at least 3 characters long so the later slicing (split into pounds and pence) works consistently for very small amounts (e.g. "5p" → "005").
+//9.This extracts everything before the last two characters of paddedPenceNumberString. Those final two characters represent pence, so everything before them is the pounds portion. Using .substring(0, length - 2) is a simple way to split the numeric string into pounds and pence.
+//14. .substring(paddedPenceNumberString.length - 2) with a single argument returns the substring from that start index to the end — i.e., the last two characters — which are the pence.
+//.padEnd(2, "0") ensures the pence string has exactly 2 characters, padding on the right if somehow it’s shorter (defensive programming). In normal flows the substring already returns 2 characters because we earlier padStart(3, "0").
+//18. console.log(`£${pounds}.${pence}`) prints the formatted price: the pound sign, the pounds portion, a dot, then the two-digit pence string.

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

@@ -11,8 +11,10 @@ In the Chrome console,
 invoke the function `alert` with an input string of `"Hello world!"`;
 
 What effect does calling the `alert` function have?
-
-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`.
+//A message that says Hello World pops up on the top of the page.
 
 What effect does calling the `prompt` function have?
+//A message saying what is your name with a box to write your name in pops up.
+
 What is the return value of `prompt`?
+//A message saying my name is with a box to write your name in pops up on the top of the page.

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

@@ -5,12 +5,18 @@ 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?
+// The 'console.log' as it is appears but with a single qoute.
+
 
 Now enter just `console` in the Console, what output do you get back?
+// 'console' is the output.
 
 Try also entering `typeof console`
+//'typeof console' is the output backticks are changed to single quotes.
 
 Answer the following questions:
 
 What does `console` store?
+// console stores a collection of functions to output.
 What does the syntax `console.log` or `console.assert` mean? In particular, what does the `.` mean?
+// `.` means that read what is inside as a string not as a function. So instead of expecting an output from `console.log` we expect it to be executed as it is as a string.

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

@@ -1,5 +1,5 @@
 // Predict and explain first...
-//  =============> write your prediction here
+// I think str is already declared even though it is a parameter.
 
 // call the function capitalise with a string input
 // interpret the error message and figure out why an error is occurring
@@ -9,5 +9,9 @@ function capitalise(str) {
   return str;
 }
 
-// =============> write your explanation here
+// The error is a syntax error at line 8 in which as I have predicted. 'str' was already declared. 
 // =============> write your new code here
+function capitalize(str) {
+  let capitalized = `${str[0].toUpperCase()}${str.slice(1)}`;
+  return capitalized;
+}

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

@@ -2,7 +2,7 @@
 
 // Why will an error occur when this program runs?
 // =============> write your prediction here
-
+// I guess decimalNumber is declared already so an error will be thrown.
 // Try playing computer with the example to work out what is going on
 
 function convertToPercentage(decimalNumber) {
@@ -15,6 +15,13 @@ function convertToPercentage(decimalNumber) {
 console.log(decimalNumber);
 
 // =============> write your explanation here
-
+// It is the same as i have predicted decimalNumber has already declared. And also there will be a reference error decimalNumber is logged outside the function. 
 // 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

@@ -4,17 +4,24 @@
 // this function should square any number but instead we're going to get an error
 
 // =============> write your prediction of the error here
+// I guess an error will be thrown because a number can not be a parameter.
 
 function square(3) {
     return num * num;
 }
-
 // =============> write the error message here
+//SyntaxError: Unexpected number
 
 // =============> explain this error message here
+// It does not know where the 3 came from. So instead of 3 it was supposed to be num.return num * num; does not work because num is not in the parameter.
 
 // 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 +1,7 @@
 // Predict and explain first...
 
 // =============> write your prediction here
+// I predict there will be error because instead of console.log we should have used return.
 
 function multiply(a, b) {
   console.log(a * b);
@@ -9,6 +10,12 @@ function multiply(a, b) {
 console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
 
 // =============> write your explanation here
+// The same as I predicted.
 
 // 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 +1,6 @@
 // Predict and explain first...
 //  =============> write your prediction here
+// there will be an error because return should not have semicolon which is the end of the declaration and a+b should be with it together.
 
 function sum(a, b) {
   return;
@@ -9,5 +10,11 @@ function sum(a, b) {
 console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
 
 // =============> write your explanation here
+// it is undefined because it stopped reading at return;
 // Finally, correct the code to fix the problem
-//  =============> write your new code here
+//  =============> write your new code here.
+function sum(a, b) {
+  return a + b;
+}
+
+console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);

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

@@ -2,6 +2,7 @@
 
 // Predict the output of the following code:
 // =============> Write your prediction here
+// I guess line 7 should have written after line 11. and the num should have been a parameter.
 
 const num = 103;
 
@@ -15,10 +16,21 @@ console.log(`The last digit of 806 is ${getLastDigit(806)}`);
 
 // Now run the code and compare the output to your prediction
 // =============> write the output here
+//The last digit of 42 is 3
+//The last digit of 105 is 3
+//The last digit of 806 is 3
 // Explain why the output is the way it is
+//every call returned "3" (the last digit of 103) instead of the number I pass because the const num was unnecessary if we wanted the function to work for any call.
 // =============> write your explanation here
 // Finally, correct the code to fix the problem
 // =============> write your new code here
+function getLastDigit(num) {
+  return num.toString().slice(-1);
+}
+
+console.log(`The last digit of 42 is ${getLastDigit(42)}`);
+console.log(`The last digit of 105 is ${getLastDigit(105)}`);
+console.log(`The last digit of 806 is ${getLastDigit(806)}`);
 
 // This program should tell the user the last digit of each number.
 // Explain why getLastDigit is not working properly - correct the problem

Sprint-2/3-mandatory-implement/1-bmi.js

@@ -15,5 +15,7 @@
 // It should return their Body Mass Index to 1 decimal place
 
 function calculateBMI(weight, height) {
-    // return the BMI of someone based off their weight and height
-}
+      const bmi = weight / (height * height);   // Step 1: calculate BMI
+    return bmi.toFixed(1);
+}
+console.log(calculateBMI(70, 1.73));

Sprint-2/3-mandatory-implement/2-cases.js

@@ -10,6 +10,16 @@
 // it returns the string in UPPER_SNAKE_CASE, so "HELLO_THERE"
 
 // Another example: "lord of the rings" should be "LORD_OF_THE_RINGS"
+function toUpperSnakeCase(str) {
+
+    const withUnderscores = str.replace(/ /g, "_");    
+
+    const upperSnake = withUnderscores.toUpperCase();
+
+    return upperSnake;
+}
+console.log(toUpperSnakeCase("hello there"));    
+console.log(toUpperSnakeCase("lord of the rings"));
 
 // You will need to come up with an appropriate name for the function
 // Use the MDN string documentation to help you find a solution

Sprint-2/3-mandatory-implement/3-to-pounds.js

@@ -4,3 +4,25 @@
 // You will need to declare a function called toPounds with an appropriately named parameter.
 
 // You should call this function a number of times to check it works for different inputs
+function toPounds(penceString) { 
+
+  const penceStringWithoutTrailingP = penceString.substring(
+    0,
+    penceString.length - 1
+  );
+
+  const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");
+
+  const pounds = paddedPenceNumberString.substring(
+    0,
+    paddedPenceNumberString.length - 2
+  );  
+
+  const pence = paddedPenceNumberString
+    .substring(paddedPenceNumberString.length - 2)
+    .padEnd(2, "0");
+
+  return `£${pounds}.${pence}`;
+}
+console.log(toPounds("399p"));
+console.log(toPounds("5p"));