Glasgow | Jan-26 | Fattouma Ouannassi | Sprint 2 | Coursework

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 = ``;
+const initials = firstName.charAt(0) + middleName.charAt(0) + lastName.charAt(0);
+console.log( `acronym = ${initials}`);
 
 // https://www.google.com/search?q=get+first+character+of+string+mdn
 

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

@@ -12,12 +12,22 @@
 const filePath = "/Users/mitch/cyf/Module-JS1/week-1/interpret/file.txt";
 const lastSlashIndex = filePath.lastIndexOf("/");
 const base = filePath.slice(lastSlashIndex + 1);
-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 lastDot = filePath.lastIndexOf(".");
+console.log(`The indexDot is ${lastDot}`);
+
+const ext = filePath.slice(lastDot);
+
+const fileName = filePath.slice(lastSlashIndex + 1, lastDot);
+const dir = filePath.slice(1, lastSlashIndex + 1);
+
+
+
+console.log(`The dir is -> ${dir}`);
+console.log(`The nameFile is -> ${fileName}`);
+console.log(`The extension is -> ${ext}`);
 
 // https://www.google.com/search?q=slice+mdn

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

@@ -7,3 +7,7 @@ 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
+Math.floor() //removes decimal part and returns whole number
+Math.random() //needs to values between minimum and maximum to generate a random number
+console.log(maximum - minimum + 1 ) + minimum; // this is same as 100 - 1 + 1 = 100 
+console.log(`The random number is ${num}`);

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

@@ -1,4 +1,5 @@
 // trying to create an age variable and then reassign the value by 1
 
-const age = 33;
+let age = 33; // I to used 'let' to reassign a variable
 age = age + 1;
+console.log(age);

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}`);
+// The variable cityOfBirth has to be before the console.log statement.

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

@@ -1,5 +1,9 @@
 const cardNumber = 4533787178994213;
-const last4Digits = cardNumber.slice(-4);
+const numberString = cardNumber.toString(); // We have to convert the cardNumber to a string first before slicing the last 4 digits.
+const last4Digits = numberString.slice(-4);
+const num = Number(last4Digits);
+
+console.log(num);
 
 // The last4Digits variable should store the last 4 digits of cardNumber
 // However, the code isn't working

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

@@ -1,2 +1,7 @@
-const 12HourClockTime = "20:53";
-const 24hourClockTime = "08:53";
+const T12HourClockTime = "20:53";
+const T24hourClockTime = "08:53";
+console.log (T12HourClockTime);
+console.log (T24hourClockTime);
+/*const 12HourClockTime = "20:53";
+const 24hourClockTime = "08:53";
+JS variable names (identifiers) must not start with a digit only start with a letter*/

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

@@ -1,22 +1,24 @@
 let carPrice = "10,000";
 let priceAfterOneYear = "8,543";
 
-carPrice = Number(carPrice.replaceAll(",", ""));
-priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ""));
+carPrice = Number(carPrice.replaceAll(",",""));
+priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", ""));
 
 const priceDifference = carPrice - priceAfterOneYear;
 const percentageChange = (priceDifference / carPrice) * 100;
 
 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 3 function (lines 4,5, and 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, the replaceAll method is missing a comma between its arguments.
 // c) Identify all the lines that are variable reassignment statements
-
+// 4 and 5)
 // d) Identify all the lines that are variable declarations
-
+// 1, 2, 7, and 8
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+/*The expression Number(carPrice.replaceAll(",", "")) first removes the commas from the string value of carPrice.
+After that, it converts the cleaned string into a number.
+The purpose is to make sure the value can be used in mathematical calculations.*/

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

@@ -12,14 +12,16 @@ 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
 // b) How many function calls are there?
-
+// There is 1 function call in the program: console.log(result)
 // c) Using documentation, explain what the expression movieLength % 60 represents
+// The expression movieLength % 60 calculates the remainder when movieLength is divided by 60.
 // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators
 
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
-
+// This line removes the leftover seconds from the total movie length and then divides the result by 60 to convert the remaining time into whole minutes.
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
-
+// The variable result stores the movie length formatted
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+// The code will work correctly for positive whole numbers representing seconds.

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

@@ -1,21 +1,24 @@
 const penceString = "399p";
-
+// initialises a string variable with the value "399p"
 const penceStringWithoutTrailingP = penceString.substring(
   0,
   penceString.length - 1
 );
-
+// Removes the final character ("p") from the string, leaving only the numeric part of the price.
 const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");
 const pounds = paddedPenceNumberString.substring(
   0,
   paddedPenceNumberString.length - 2
 );
-
+// Ensures the string has at least three characters by adding leading zeros if necessary.
 const pence = paddedPenceNumberString
   .substring(paddedPenceNumberString.length - 2)
   .padEnd(2, "0");
+  //Takes the last two digits as the pence part and ensures it is exactly two characters long.
+
 
 console.log(`£${pounds}.${pence}`);
+// Combines the pounds and pence into a formatted currency string and outputs the final result in pounds (£)
 
 // This program takes a string representing a price in pence
 // The program then builds up a string representing the price in pounds

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

@@ -1,13 +1,15 @@
 // Predict and explain first...
-//  =============> write your prediction here
+//  =============> When we call capitalise("hello"), it will throw an error instead of returning "Hello".
 
 // 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;
+// =============> "str" has already been declared, in JavaScript we can not redeclare a parameter using let inside the same scope.
+// =============>
+
+  function capitalise(str) {
+
+  return `${str[0].toUpperCase()}${str.slice(1)}`;
 }
 
-// =============> write your explanation here
-// =============> write your new code here
+console.log(capitalise("hello")); 

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

@@ -1,20 +1,19 @@
 // Predict and explain first...
 
 // Why will an error occur when this program runs?
-// =============> write your prediction here
+// =============> An error will occur because console.log(decimalNumber) tries to access a variable that does not exist in the global scope.
 
 // Try playing computer with the example to work out what is going on
 
-function convertToPercentage(decimalNumber) {
-  const decimalNumber = 0.5;
-  const percentage = `${decimalNumber * 100}%`;
-
-  return percentage;
-}
 
-console.log(decimalNumber);
 
-// =============> write your explanation here
+// =============> decimalNumber is already a parameter, and JavaScript does not allow redeclaring a parameter woth const.
 
 // 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

@@ -3,18 +3,19 @@
 
 // this function should square any number but instead we're going to get an error
 
-// =============> write your prediction of the error here
+// =============> SyntaxError
 
-function square(3) {
-    return num * num;
-}
 
-// =============> write the error message here
+// =============> Unexpected number
 
-// =============> explain this error message here
+// =============> function parameters must be variable not values.
 
 // 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

@@ -1,14 +1,13 @@
 // Predict and explain first...
 
-// =============> write your prediction here
+// =============> SyntaxError undefined function
 
-function multiply(a, b) {
-  console.log(a * b);
-}
-
-console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
 
-// =============> write your explanation here
+// =============> We use console.log() only when we want to print something immediately. In this case we need to use return.
 
 // 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

@@ -1,13 +1,12 @@
 // Predict and explain first...
-//  =============> write your prediction here
+//  =============> the sum is undefined
 
-function sum(a, b) {
-  return;
-  a + b;
-}
-
-console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
 
-// =============> write your explanation here
+// =============> This is due to Automatic semicolon Insertion
 // 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 + 32 is ${sum(10, 32)}`);

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

@@ -1,24 +1,31 @@
 // Predict and explain first...
 
 // Predict the output of the following code:
-// =============> Write your prediction here
+// =============> The output will always be 3 for all cases.
 
+
+// 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
+// =============> write your explanation here
+//The function does not have a parameter.
+//It does not use the values 42, 105, or 806.
+//It always uses the global variable:
+// Finally, correct the code to fix the problem
+// =============> write your new code here
 const num = 103;
 
-function getLastDigit() {
-  return num.toString().slice(-1);
+function getLastDigit(value) {
+  return value.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)}`);
 
-// Now run the code and compare the output to your prediction
-// =============> write the output here
-// Explain why the output is the way it is
-// =============> write your explanation here
-// Finally, correct the code to fix the problem
-// =============> write your new code here
 
 // 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 +15,8 @@
 // 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 squareHeight = height * height;
+  const bmi = weight / squareHeight;
+  return Number(bmi.toFixed(1));
+}
+console.log(calculateBMI(60, 1.70));

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

@@ -14,3 +14,9 @@
 // You will need to come up with an appropriate name for the function
 // Use the MDN string documentation to help you find a solution
 // This might help https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/toUpperCase
+function toUpperSnakeCase(str) {
+     return str.toUpperCase().replaceAll(" ", "_");
+}
+
+console.log(toUpperSnakeCase("Hello there")); // "HELLO_THERE"
+console.log(toUpperSnakeCase("lord of the rings")); // "LORD_OF_THE_RINGS"