Complete all mandatory-debug exercises

Author: ausiejute

Sprint-3/1-key-errors/0.js

@@ -1,13 +1,20 @@
 // Predict and explain first...
-//  =============> write your prediction here
+//  =============> If the function will be called, it will print the first letter of the string
+// in capital with the rest of the word in lowercase
 
 // call the function capitalise with a string input
 // interpret the error message and figure out why an error is occurring
 
-function capitalise(str) {
+/* function capitalise(str) {
   let str = `${str[0].toUpperCase()}${str.slice(1)}`;
   return str;
+} */
+
+// =============> A SyntaxError was thrown because the str was used to name both the function parameter
+// and a new variable, which cannot happen in 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("mother"));

Sprint-3/1-key-errors/1.js

@@ -1,20 +1,25 @@
 // Predict and explain first...
+// There will be another syntax error, because the same name is used for both the parameter and the variable
+// (decimalNumber)
 
 // Why will an error occur when this program runs?
-// =============> write your prediction here
+// =============>
+// We cannot redeclare a variable with the same name in the same scope.
 
 // Try playing computer with the example to work out what is going on
 
-function convertToPercentage(decimalNumber) {
+/* function convertToPercentage(decimalNumber) {
   const decimalNumber = 0.5;
   const percentage = `${decimalNumber * 100}%`;
 
   return percentage;
 }
-
-console.log(decimalNumber);
+*/
 
 // =============> write your explanation here
+// We create a function that takes a decimal number as a parameter, then declare a variable and assign value to it,
+// then create a variable named "percentage", the value of which is calculated by calculating the decimal number
+// and multiplying it by 100. Finally, we return the output - percentage.
 
 // Finally, correct the code to fix the problem
 // =============> write your new code here

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

@@ -4,17 +4,19 @@
 // this function should square any number but instead we're going to get an error
 
 // =============> write your prediction of the error here
+// I predict it will say 'num is not defined'
 
 function square(3) {
     return num * num;
 }
 
 // =============> write the error message here
-
+// SyntaxError: Unexpected number
 // =============> explain this error message here
-
+// 
 // Finally, correct the code to fix the problem
 
 // =============> write your new code here
 
 
+console.log(square(3));

Sprint-3/2-mandatory-debug/0.js

@@ -1,6 +1,7 @@
 // Predict and explain first...
 
-// =============> write your prediction here
+// =============>
+// Variables haven't been declared, so it will throw a reference error
 
 function multiply(a, b) {
   console.log(a * b);
@@ -9,6 +10,13 @@ function multiply(a, b) {
 console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
 
 // =============> write your explanation here
-
+// It printed 32 because that particular console function is inside the multiply function (local), whereas the other one
+// is outside the scope and when we call the multiply function it comes up as undefined because nothing has been returned
+// inside of it.
 // 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-3/2-mandatory-debug/1.js

@@ -1,13 +1,21 @@
 // Predict and explain first...
 //  =============> write your prediction here
+// it will print the following: `The sum of 10 and 32 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
+// the function sum doesn't return any value. The arithmetic operation doesn't execute because it's defined after 'return'
 // 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-3/2-mandatory-debug/2.js

@@ -2,8 +2,8 @@
 
 // Predict the output of the following code:
 // =============> Write your prediction here
-
-const num = 103;
+// it will not print the correct last digits
+/*const num = 103;
 
 function getLastDigit() {
   return num.toString().slice(-1);
@@ -12,13 +12,29 @@ 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)}`);
+*/
 
 // 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
+
+// Because the method uses the num value which is 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
+// The function getLastDigit wasn't using intended parameters