Sheffield | May-2025 | WALEED-YAHYA SALIH-TAHA | Sprint-2

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

@@ -1,13 +1,24 @@
 // Predict and explain first...
 //  =============> write your prediction here
+// The code will throw an error because the variable 'str' is being redeclared with 'let' inside the function,
+// which is not allowed since 'str' is already defined as a parameter of the function.
 
 // 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;
+// }
+
+// =============> write your explanation here
+// The error occurs because the variable 'str' is being declared again with 'let' inside the function,
+// which conflicts with the parameter 'str' that is already defined. In JavaScript, you cannot redeclare a variable with 'let' in the same scope.
+// =============> write your new code here
 function capitalise(str) {
-  let str = `${str[0].toUpperCase()}${str.slice(1)}`;
+  str = `${str[0].toUpperCase()}${str.slice(1)}`;
   return str;
 }
+console.log(capitalise("hello"));  // Output: "Hello"
+
 
-// =============> write your explanation here
-// =============> write your new code here

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

@@ -2,19 +2,29 @@
 
 // Why will an error occur when this program runs?
 // =============> write your prediction here
+// The code will throw an error because the variable 'decimalNumber' is being redeclared with 'const' inside the function,
+// which is not allowed since 'decimalNumber' is already defined as a parameter of the function
 
 // Try playing computer with the example to work out what is going on
 
-function convertToPercentage(decimalNumber) {
-  const decimalNumber = 0.5;
-  const percentage = `${decimalNumber * 100}%`;
-
-  return percentage;
-}
+// function convertToPercentage(decimalNumber) {
+//   const decimalNumber = 0.5;
+//   const percentage = `${decimalNumber * 100}%`;
 
-console.log(decimalNumber);
+//   return percentage;
+// }
+// console.log(decimalNumber);
 
 // =============> write your explanation here
+// The error occurs because the variable 'decimalNumber' is being declared again with 'const' inside the function,
+// which conflicts with the parameter 'decimalNumber' that is already defined. In JavaScript,
 
 // Finally, correct the code to fix the problem
 // =============> write your new code here
+function convertToPercentage(decimalNumber) {
+  decimalNumber = 0.5; // Remove 'const' to avoid redeclaration
+  const percentage = `${decimalNumber * 100}%`;
+
+  return percentage;
+}
+console.log(convertToPercentage(0.5)); // Output: "50%"

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

@@ -4,17 +4,26 @@
 // this function should square any number but instead we're going to get an error
 
 // =============> write your prediction of the error here
+// The code will throw an error because the function is trying to use a number literal (3) as a parameter name,
+// which is not allowed in JavaScript. Function parameters must be valid identifiers, and a number
 
-function square(3) {
-    return num * num;
-}
+// function square(3) {
+//     return num * num;
+// }
 
 // =============> write the error message here
+// SyntaxError: Unexpected number in parameter list
 
 // =============> explain this error message here
+// The error message indicates that there is a syntax error because the function parameter cannot be a number.
+// Function parameters must be valid identifiers, and using a number as a parameter name is not allowed
 
 // Finally, correct the code to fix the problem
 
 // =============> write your new code here
+function square(num) {
+    return num * num;
+}
+console.log(square(3)); // Output: 9
 
 

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

@@ -1,14 +1,25 @@
 // Predict and explain first...
 
 // =============> write your prediction here
+// This code will not produce the expected string output. Instead, it will:
+// Log the result of the multiplication directly (320)
+// Then print:The result of multiplying 10 and 32 is undefined
 
-function multiply(a, b) {
-  console.log(a * b);
-}
+// function multiply(a, b) {
+//   console.log(a * b);
+// }
 
-console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
+// console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
 
 // =============> write your explanation here
+// multiply(10, 32) runs inside the template literal.
+// Inside the multiply function, console.log(a * b) prints 320 to the console.
+// However, the multiply function does not return a value → so it returns undefined by default.
 
 // Finally, correct the code to fix the problem
+//You should return the result from the function instead of logging it directly:
+function multiply(a, b) {
+  return a * b;
+}
+console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
 //  =============> write your new code here

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

@@ -1,13 +1,22 @@
 // Predict and explain first...
 //  =============> write your prediction here
+// This code will output:
+// The sum of 10 and 32 is undefined
+// because the sum function does not return a value.
+// function sum(a, b) {
+//   return;
+//   a + b;
+// }
 
-function sum(a, b) {
-  return;
-  a + b;
-}
-
-console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
+// console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
 
 // =============> write your explanation here
+// The sum function does not return a value because the return statement is immediately followed by a semicolon.
+// This means the function exits before it can execute the a + b expression.
+
 // Finally, correct the code to fix the problem
+function sum(a, b) {
+  return a + b; // Corrected to return the sum of a and b
+}
+console.log(`The sum of 10 and 32 is ${sum(10, 32)}`); // Output: The sum of 10 and 32 is 42
 //  =============> write your new code here

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

@@ -2,23 +2,47 @@
 
 // Predict the output of the following code:
 // =============> Write your prediction here
+// The last digit of 42 is undefined
+// The last digit of 105 is undefined
+// The last digit of 806 is undefined
 
-const num = 103;
 
-function getLastDigit() {
-  return num.toString().slice(-1);
-}
+// const num = 103;
 
-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)}`);
+// function getLastDigit() {
+//   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)}`);
 
 // Now run the code and compare the output to your prediction
 // =============> write the output here
+// The last digit of 42 is undefined
+// The last digit of 105 is undefined
+// The last digit of 806 is undefined
 // Explain why the output is the way it is
 // =============> write your explanation here
+// The output is undefined because the getLastDigit function does not accept any parameters.
+// It always uses the global variable num, which is set to 103.
+// The function getLastDigit should take a number as an argument and return its last digit.
+
 // Finally, correct the code to fix the problem
 // =============> write your new code here
 
+function getLastDigit(num) {
+  return num.toString().slice(-1);
+}
+
+
 // This program should tell the user the last digit of each number.
+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)}`);
+
 // Explain why getLastDigit is not working properly - correct the problem
+// =============> write your explanation here
+// The getLastDigit function was not accepting any parameters.
+
+