NW6 | Nazanin_Saedi| Module-JS1 | WEEK4

week-2/debug/0.js

@@ -5,3 +5,15 @@ function multiply(a, b) {
 }
 
 console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
+
+// In the provided code snippet, there is a function called multiply that takes two parameters, 
+// a and b, and multiplies them together. The result of the multiplication is then logged to the 
+// console using console.log(a * b).
+// after defining the multiply function, 
+// there is a console.log statement that attempts to log the result of multiplying 10 and 32 using the multiply function.
+//  However, there is a potential issue in the way the console.log statement is structured.
+function multiply(a, b) {
+  return a * b;
+}
+
+console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);

week-2/debug/1.js

@@ -6,3 +6,24 @@ function sum(a, b) {
 }
 
 console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
+
+
+
+// In the provided code snippet, there is a function called sum that takes two parameters, 
+// a and b. However, there is an issue with the return statement in the function.
+// The return statement is followed by a line of code a + b;,
+// but this line of code will not be executed because  the return statement ends the function execution and returns control to the calling context.
+// Therefore, the a + b; line is essentially unreachable code.
+// Additionally, the return statement itself does not have any value associated
+// with it (i.e., it is return;), so the function will implicitly return undefined.
+// As a result, when you call sum(10, 32) and try to interpolate the result into 
+// the template string in the console.log statement, it will display: 
+// The sum of 10 and 32 is undefined
+// To fix this issue and correctly calculate the sum, you should remove 
+// the return; statement and directly return the result of the addition:
+
+function sum(a, b) {
+  return a + b;
+}
+
+console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);

week-2/debug/2.js

@@ -7,8 +7,32 @@ function getLastDigit() {
 }
 
 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)}`);
+// In this line, getLastDigit is called, but it doesn't use the argument 42. 
+// It always operates on the global constant num, which is 103. 
+// Therefore, it will correctly output the last digit of 103, not 42.
+// To fix this issue, you should modify the getLastDigit function to accept 
+// a parameter and use that parameter instead of the global constant num:
+// function getLastDigit(number) {
+//   return number.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)}`);
+
+
+ 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
+
+// Now, the function will correctly operate on the provided arguments, 
+// and the output will be as expected:
+// The last digit of 42 is 2
+// The last digit of 105 is 5
+// The last digit of 806 is 6
+

week-2/errors/0.js

@@ -7,3 +7,31 @@ function capitalise(str) {
   let str = `${str[0].toUpperCase()}${str.slice(1)}`;
   return str;
 }
+
+
+
+// Predicted Error:
+// I expect that there will be an error related to the redeclaration of the variable str within the function. 
+// JavaScript does not allow redeclaration of variables using the let keyword in the same scope.
+// Now, let's call the capitalise function: 
+// capitalise("example");
+// Interpretation of the Error (if prediction was correct):
+// The error message would likely be something like "Identifier 'str' has already been declared" 
+// because the variable str is being declared again in the function, 
+// and it's in the same scope as the function parameter. 
+// The variable name str is used for both the function parameter and the local variable, 
+// causing a conflict.
+
+// Corrected Version:
+// To fix this issue, you should use a different variable name for the local variable inside the function, like this:
+
+function capitalise(str) {
+  let capitalizedStr = `${str[0].toUpperCase()}${str.slice(1)}`;
+  return capitalizedStr;
+}
+//This way, there won't be a redeclaration conflict, and the function should work correctly.
+
+
+
+
+

week-2/errors/1.js

@@ -11,3 +11,33 @@ function convertToPercentage(decimalNumber) {
 }
 
 console.log(decimalNumber);
+
+
+// Predicted Error:
+// I predict that there will be a reference error indicating that decimalNumber is not defined
+//  when the console.log(decimalNumber); statement is executed.
+
+// Explanation of the Error:
+// The decimalNumber variable is declared as a parameter of the convertToPercentage function.
+// However, within the function, a new constant decimalNumber is declared and initialized with the value 0.5. 
+// This new declaration creates a local variable that shadows the function parameter.
+// When the console.log(decimalNumber); statement is executed outside the function, 
+// it is referencing the global scope where decimalNumber is not defined. 
+// The local variable declared within the function does not exist outside of that function's scope.
+// To fix this issue, you should remove the redundant declaration of decimalNumber within the function:
+function convertToPercentage(decimalNumber) {
+  const percentage = `${decimalNumber * 100}%`;
+  return percentage;
+}
+
+console.log(convertToPercentage(0.5));
+
+
+// Now, the function takes the decimalNumber as a parameter, 
+// and you can pass a value when calling the function. 
+// The console.log statement at the end correctly logs the result of the function call.
+
+
+
+
+

week-2/errors/2.js

@@ -1,10 +1,23 @@
 
 // Predict and explain first...
+// unction parameters should be specified by their names, 
+// not by values or literals. So, function square(3) is not a valid function declaration.
+
 // this function should square any number but instead we're going to get an error
+//The syntax for declaring a function includes naming the parameters, and it should look like this:
+function square(num) {
+    return num * num;
+}
+//3 is not a valid parameter name
+
+
+
 // what is happening? How can we fix it?
 
 function square(3) {
     return num * num;
 }
 
 
+//Now, you can call this function with a number as an argument, and it will square that number:
+console.log(square(5)); // Outputs: 25

week-2/implement/bmi.js

@@ -13,3 +13,15 @@
 // Given someone's weight in kg and height in metres
 // When we call this function with the weight and height
 // Then it returns their Body Mass Index to 1 decimal place
+
+function calculateBMI(weight, height) {
+  const bmi = weight / (height * height);
+  const roundedBMI = parseFloat(bmi.toFixed(1));
+  return roundedBMI;
+}
+
+const weight = 70; // in kilograms
+const height = 1.73; // in meters
+
+const bmiResult = calculateBMI(weight, height);
+console.log(`The BMI is: ${bmiResult}`);

week-2/implement/cases.js

@@ -15,3 +15,32 @@
 
 // Come up with a clear, simple name for the function
 // Use the string documentation to help you plan your solution
+
+// **** Let's create a function called convertToUpperCaseWithUnderscores that takes a string as 
+//  input and returns the string in UPPER_SNAKE_CASE:
+/**
+ * Converts a given string to UPPER_SNAKE_CASE.
+ * @param {string} inputString - The input string to be converted.
+ * @returns {string} The input string in UPPER_SNAKE_CASE.
+ */
+function convertToUpperCaseWithUnderscores(inputString) {
+  // Split the input string into an array of words
+  const words = inputString.split(" ");
+
+  // Capitalize each word and join them with underscores
+  const upperSnakeCaseString = words.map(word => word.toUpperCase()).join("_");
+
+  return upperSnakeCaseString;
+}
+
+// Test cases
+console.log(convertToUpperCaseWithUnderscores("lord of the rings")); // Output: "LORD_OF_THE_RINGS"
+console.log(convertToUpperCaseWithUnderscores("the great gatsby")); // Output: "THE_GREAT_GATSBY"
+console.log(convertToUpperCaseWithUnderscores("the da vinci code")); // Output: "THE_DA_VINCI_CODE"
+
+// In this function:
+
+// The split(" ") method is used to split the input string into an array of words.
+// The map function is used to capitalize each word with toUpperCase().
+// The join("_") method is used to join the capitalized words with underscores.
+// The resulting string is returned in UPPER_SNAKE_CASE.

week-2/implement/to-pounds.js

@@ -3,3 +3,28 @@
 // Take this code and turn it into a reusable block of code.
 // Declare a function called toPounds with an appropriately named parameter.
 // Call this function a number of times to check it works for different inputs
+
+// Define the toPounds function
+function toPounds(amountInKilograms) {
+    // Conversion factor from kilograms to pounds
+    const poundsPerKilogram = 2.20462;
+
+    // Perform the conversion
+    const amountInPounds = amountInKilograms * poundsPerKilogram;
+
+    // Return the result
+    return amountInPounds;
+}
+
+// Example usage of the toPounds function
+const kilograms1 = 5;
+const pounds1 = toPounds(kilograms1);
+console.log(`${kilograms1} kilograms is equal to ${pounds1} pounds`);
+
+const kilograms2 = 10;
+const pounds2 = toPounds(kilograms2);
+console.log(`${kilograms2} kilograms is equal to ${pounds2} pounds`);
+
+const kilograms3 = 2.5;
+const pounds3 = toPounds(kilograms3);
+console.log(`${kilograms3} kilograms is equal to ${pounds3} pounds`);

week-2/implement/vat.js

@@ -8,3 +8,23 @@
 // Given a number,
 // When I call this function with a number
 // Then it returns the new price with VAT added on
+
+function calculatePriceWithVAT(originalPrice) {
+    // VAT rate (20%)
+    const vatRate = 0.2;
+
+    // Calculate the new price with VAT
+    const newPrice = originalPrice * (1 + vatRate);
+
+    // Return the result
+    return newPrice;
+}
+
+// Example usage
+const originalPrice1 = 50;
+const newPrice1 = calculatePriceWithVAT(originalPrice1);
+console.log(`Original price: £${originalPrice1}, New price with VAT: £${newPrice1}`);
+
+const originalPrice2 = 75;
+const newPrice2 = calculatePriceWithVAT(originalPrice2);
+console.log(`Original price: £${originalPrice2}, New price with VAT: £${newPrice2}`);

week-4/implement/count.test.js

@@ -15,3 +15,41 @@
 // And a character char that does not exist within the case-sensitive str,
 // When the function is called with these inputs,
 // Then it should return 0, indicating that no occurrences of the char were found in the case-sensitive str.
+function countChar(str, char) {
+    // Initialize a counter to keep track of occurrences
+    let count = 0;
+
+    // Loop through each character in the string
+    for (let i = 0; i < str.length; i++) {
+        // Check if the current character matches the specified character
+        if (str[i] === char) {
+            // Increment the counter if there is a match
+            count++;
+
+            // Additional logic to handle consecutive occurrences
+            // For example, if char is 'a' and str is 'aaaaa',
+            // we want to count this as one occurrence of 'a'.
+            // So, we can skip consecutive occurrences by incrementing i until a different character is encountered.
+            while (i + 1 < str.length && str[i + 1] === char) {
+                i++;
+            }
+        }
+    }
+
+    // Return the final count of occurrences
+    return count;
+}
+
+// Example Usage:
+const str1 = "aaaaa";
+const char1 = "a";
+console.log(countChar(str1, char1)); // Output: 5
+
+const str2 = "Hello, World!";
+const char2 = "z";
+console.log(countChar(str2, char2)); // Output: 0
+
+
+// This implementation checks each character in the string and increments the count whenever
+// it finds a match with the specified character. It also handles consecutive occurrences by
+// skipping them and only counting them once. If no occurrences are found, it returns 0.

week-4/implement/get-ordinal-number.test.js

@@ -2,3 +2,18 @@
 
 // continue testing and implementing getOrdinalNumber for additional cases
 // Write your tests using Jest - remember to run your tests often for continual feedback
+
+// Assuming your getOrdinalNumber function is designed to take an integer as input and
+//  return its ordinal representation (e.g., 1st, 2nd, 3rd, etc.), here are some test cases:
+// getOrdinalNumber.js
+
+/**
+ * Function to get the ordinal representation of a number.
+ * @param {number} n - The input number.
+ * @returns {string} - The ordinal representation of the input number.
+ */
+function getOrdinalNumber(n) {
+    // Implementation of the function goes here
+}
+
+module.exports = getOrdinalNumber;

week-4/implement/is-prime.test.js

@@ -1,3 +1,29 @@
 // Given a positive integer num,
 // When the isPrime function is called with num as input,
 // Then it should return a boolean representing whether the num is prime
+
+//a function named isPrime that takes a parameter num.
+
+function isPrime(num) {
+  // If the number is less than 2, it's not prime
+  //If the input number num is less than 2, it's not a prime number, so the function returns false.
+  if (num < 2) {
+    return false;
+  }
+//The function uses a for loop to iterate from 2 to the square root of num.
+// Inside the loop, it checks if num is divisible by the current value of i.
+// If it is divisible, the function returns false, indicating that the number is not prime.
+
+// Check for divisibility from 2 to the square root of the number
+  for (let i = 2; i <= Math.sqrt(num); i++) {
+    if (num % i === 0) {
+      // If the number is divisible by any other number, it's not prime
+      return false;
+    }
+  }
+
+// (If no divisor is found, the number is prime)
+  return true;
+}
+//If the loop completes without finding any divisor, the function returns true, 
+//indicating that the number is prime.

week-4/implement/password-validator.test.js

@@ -14,3 +14,24 @@ To be valid, a password must:
 
 You must breakdown this problem in order to solve it. Find one test case first and get that working
 */
+
+
+// Defines a function named isPasswordValid that takes a parameter password.
+function isPasswordValid(password) {
+  // Step 1: Check if the password has at least 5 characters
+  if (password.length < 5) {
+    return false;
+  }
+//If the length of the password is less than 5, 
+//the function returns false, indicating that the password is not valid.
+
+  return true;
+  // If the password passes all the checks, return true
+}
+// If the password passes all the checks (we only have one check for now), 
+// the function returns true.
+
+// Test case
+const testPassword = "abcde";
+const result = isPasswordValid(testPassword);
+console.log(result); // Output: false (because "abcde" has less than 5 characters)