WESTMIDLANDS| ITP-MAY 2025| ROJA ALAGURAJAN| Module Structuring and Testing Data|sprint 2

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

@@ -1,5 +1,5 @@
 // Predict and explain first...
-//  =============> write your prediction here
+//  This code will cause a SyntaxError because the variable `str` is being declared twice within the same function scope.
 
 // call the function capitalise with a string input
 // interpret the error message and figure out why an error is occurring
@@ -10,4 +10,13 @@ function capitalise(str) {
 }
 
 // =============> write your explanation here
+// Explanation:
+// The function parameter is named `str`. Inside the function, the same name `str` is redeclared with `let`.
+// JavaScript does not allow redeclaring a variable in the same scope with `let` or `const`, so this causes a SyntaxError.
+// The error message would say something like: "Identifier 'str' has already been declared".
+
 // =============> write your new code here
+function capitalise(str) {
+  const result = `${str[0].toUpperCase()}${str.slice(1)}`;
+  return result;
+}

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

@@ -1,12 +1,13 @@
-// Predict and explain first...
-
+// Predict and explain first.:- SyntaxError because the variable 'decimalNumber' is being declared twice
 // Why will an error occur when this program runs?
-// =============> write your prediction here
+
+      // The first decimalNumber is a function parameter and the second decimalNumber is declared using const inside the function body.
+     //JavaScript does not allow a const or let declaration to reuse the name of a parameter in the same scope.
 
 // Try playing computer with the example to work out what is going on
 
 function convertToPercentage(decimalNumber) {
-  const decimalNumber = 0.5;
+  const decimalNumber= 0.5;
   const percentage = `${decimalNumber * 100}%`;
 
   return percentage;
@@ -15,6 +16,17 @@ function convertToPercentage(decimalNumber) {
 console.log(decimalNumber);
 
 // =============> write your explanation here
+  /*The error happens because the variable name 'decimalNumber' is being used twice in the same function scope: 
+  once as a parameter, and once as a const variable. 
+  note:- JavaScript does not allow redeclaring a parameter name using const or let. 
+  To fix the error, so, we should either rename the internal variable, or just use the parameter directly.*/
 
 // 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

@@ -1,20 +1,22 @@
 
-// Predict and explain first BEFORE you run any code...
+// Predict and explain first BEFORE you run any code:- 
+// its SyntaxError: Unexpected number because its invalid parameter 
 
-// this function should square any number but instead we're going to get an error
-
-// =============> write your prediction of the error here
 
 function square(3) {
     return num * num;
 }
 
-// =============> write the error message here
+// =============> write the error message :-SyntaxError: Unexpected number
 
-// =============> explain this error message here
+// =============> explain this error message here:- its SyntaxError: Unexpected number because the parameter '3' is a number literal, but function parameters must be valid variable names.
+// this function should square any number but instead we're going to get an error
 
-// Finally, correct the code to fix the problem
 
-// =============> write your new code here
+// Finally, correct the code to fix the problem\
 
+function square(num) {
+    return num * num;
+}
 
+console.log(square(3))

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

@@ -1,14 +1,21 @@
-// Predict and explain first...
-
-// =============> write your prediction here
+// Predict and explain first:--\
+// The multiply function logs the product of a and b but does not return anything.So the console.log will print:
+//The result of multiplying 10 and 32 is undefined
 
 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
+// he function multiply(a, b) uses console.log to output the product but does not have a return statement.
 
 // Finally, correct the code to fix the problem
-//  =============> write your new code here
+
+
+
+function multiply(a, b) {
+  return a * b;  // Return the product instead of logging it
+}
+
+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
+// Predict and explain first... 
+//  The function sum(a, b) includes a return statement followed by a line with 'a + b'.
+// error:-The sum of a and b is undefined 
 
 function sum(a, b) {
   return;
@@ -8,6 +9,13 @@ function sum(a, b) {
 
 console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
 
-// =============> write your explanation here
+// The return statement ends before 'a + b' due to JavaScript's automatic semicolon insertion.
+// As a result, the function returns undefined and 'a + b' is never executed.
+
 // 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)}`);

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

@@ -1,7 +1,10 @@
+
 // Predict and explain first...
 
 // Predict the output of the following code:
-// =============> Write your prediction here
+//I predict that the output of this code will not be as expected because the variable num has been declared with a value and it cannot be changed because it is a constant variable. 
+// There is also no parameter in the getLastDigit function. So even though the console.log statements are trying to call the getLastDigit function with different arguments,
+// the function will not return any of the sliced version of these values.
 
 const num = 103;
 
@@ -14,11 +17,27 @@ 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
+/* 
+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 fact that 3 is the result of each console.log statement is because the getLastDigit function is not actually using the arguments of 42, 105, and 806. 
+Instead, because the num variable was assigned with 103 */
+
 // 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
+/*Originally the getLastDigit function didn't have a parameter to accept an argument, 
+so it will always use the constant num variable defined at the top of the script to evaluate the last digit. 
+*/

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

@@ -14,6 +14,13 @@
 // Then when we call this function with the weight and height
 // It should return their Body Mass Index to 1 decimal place
 
-function calculateBMI(weight, height) {
+function calculateBMI(weightKg, heightM) {
     // return the BMI of someone based off their weight and height
-}
+    square=(heightM*heightM);
+    const bmi = weightKg / square;
+    // return the BMI to 1 decimal 
+  return bmi.toFixed(1);
+
+}
+console.log(`The BMI of a person with a weight of 70kg and a height of 1.73m is ${calculateBMI(70, 1.73 )}`);
+// logs "The BMI of a person with a weight of 70kg and a height of 1.73m is 23.4" to the console.

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

@@ -14,3 +14,14 @@
 // 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
+
+/* I create a function named strToUppersnakeCase that replaces spaces with underscores, 
+ and then call the function in the console to print the result  */
+
+ function strToUppersnakeCase(str) {
+  return str.toUpperCase().replace(/\s+/g, "_");
+}
+
+// Calling the function and printing the result in the console
+console.log(strToUppersnakeCase("hello there"));
+console.log(strToUppersnakeCase("lord of the rings"));

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

@@ -4,3 +4,45 @@
 // 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
+
+/*const penceString = "399p";// Initializes the string and extracts all characters except the trailing 'p'
+const penceStringWithoutTrailingP = penceString.substring(0,penceString.length - 1);
+const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0"); 
+const pounds = paddedPenceNumberString.substring(0, paddedPenceNumberString.length - 2);   // Extracts the pounds part by taking all digits except the last two
+const pence = paddedPenceNumberString.substring(paddedPenceNumberString.length - 2).padEnd(2, "0"); // Extracts the pence portion of the price by taking the last two digits and ensures it has exactly two digits.
+console.log(`£${pounds}.${pence}`); */
+
+function toPounds(pence) {
+  if (typeof pence !== "string" || !pence.endsWith("p")) {
+    return "Invalid input. The input must be a string ending with 'p'.";
+  }
+
+  const penceStringWithoutTrailingP = pence.substring(0, pence.length - 1);
+  const penceNumber = Number(penceStringWithoutTrailingP);
+
+  if (Number.isInteger(penceNumber) && penceNumber >= 0) {
+    const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(
+      3,
+      "0"
+    );
+    const pounds = paddedPenceNumberString.substring(
+      0,
+      paddedPenceNumberString.length - 2
+    );
+
+    const pennies = paddedPenceNumberString
+      .substring(paddedPenceNumberString.length - 2)
+      .padEnd(2, "0");
+
+    return `£${pounds}.${pennies}`;
+  } else {
+    return "Invalid input. The pence amount must be in number format and must be whole numbers that are not less than 0";
+  }
+}
+
+console.log(toPounds("5498p")); //result is £54.98
+console.log(toPounds("63p")); //result is £0.63
+console.log(toPounds("5498")); //result is "Invalid input. The input must be a string ending with 'p'."
+console.log(toPounds("-99p")); //result is "Invalid input. The pence amount must be in number format and must be whole numbers that are not less than 0"
+console.log(toPounds("pp")); //result is "Invalid input. The pence amount must be in number format and must be whole numbers that are not less than 0"
+console.log(toPounds("12.7p")); //Invalid input. The pence amount must be in number format and must be whole numbers that are not less than 0

Sprint-2/4-mandatory-interpret/time-format.js

@@ -17,18 +17,29 @@ function formatTimeDisplay(seconds) {
 // Questions
 
 // a) When formatTimeDisplay is called how many times will pad be called?
-// =============> write your answer here
+//   3 times
+ //(Once each for totalHours, remainingMinutes, and remainingSeconds)
+
+
 
 // Call formatTimeDisplay with an input of 61, now answer the following:
+//console.log(formatTimeDisplay(61)); //result is "00:01:01"
 
 // b) What is the value assigned to num when pad is called for the first time?
-// =============> write your answer here
+//    0
+  //(The value of totalHours)
+
+
 
 // c) What is the return value of pad is called for the first time?
-// =============> write your answer here
+// "00"
+//(0.toString().padStart(2, "0") → "00")
 
 // d) What is the value assigned to num when pad is called for the last time in this program?  Explain your answer
-// =============> write your answer here
+//  1
+//The value assigned to num when pad is called for the last time is 1. This is because the function takes an input of 61 
+// and the remainingSeconds variable takes the remainder when 61 is divided by 60 .or in other words the number of seconds left after dividing 61 seconds into full minutes
 
 // e) What is the return value assigned to num when pad is called for the last time in this program?  Explain your answer
-// =============> write your answer here
+// "01"
+//(1.toString().padStart(2, "0") → "01")