kolya-rm · kolya-rm · Dec 9, 2025 · Dec 9, 2025 · Dec 9, 2025 · Dec 10, 2025
diff --git a/Sprint-2/1-key-errors/0.js b/Sprint-2/1-key-errors/0.js
@@ -1,13 +1,31 @@
 // Predict and explain first...
 //  =============> write your prediction here
+// 
+// We'll get syntax error with variable declaration. Function already have 
+// the variable str as a parameter. Then we try to declare another variable with
+// the same name in the function body.
 
 // 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;
-}
+// function capitalise(str) {
+//   let str = `${str[0].toUpperCase()}${str.slice(1)}`;
+//   return str;
+// }
+// 
+// capitalise("module structuring and testing data");
 
 // =============> write your explanation here
+//
+// As predicted we cath error 'SyntaxError: Identifier 'str' has already been declared'
+//
 // =============> write your new code here
+
+function capitalise(str) {
+  let resultStr = `${str[0].toUpperCase()}${str.slice(1)}`;
+  return resultStr;
+}
+
+console.log(capitalise("module structuring and testing data"));
+
+
diff --git a/Sprint-2/1-key-errors/1.js b/Sprint-2/1-key-errors/1.js
@@ -2,19 +2,39 @@
 
 // Why will an error occur when this program runs?
 // =============> write your prediction here
-
+//
+// We'll get a syntax error with redeclaration of the exist variable. The variable
+// decimalNumber is already declared as a parameter of the function, but then we
+// try to declare and initialize new constant with the same name. Other problem
+// is that we try to use in the console.log() function invocation variable declared
+// inside the function and don't accessible from global scope.
+//
 // Try playing computer with the example to work out what is going on
 
+// function convertToPercentage(decimalNumber) {
+//   const decimalNumber = 0.5;
+//   const percentage = `${decimalNumber * 100}%`;
+
+//   return percentage;
+// }
+
+// console.log(decimalNumber);
+
+// =============> write your explanation here
+//
+// As predicted we got an error 'SyntaxError: Identifier 'decimalNumber' has 
+// already been declared'. But solution depends of logic of the function.
+//
+// Finally, correct the code to fix the problem
+// =============> write your new code here
+
+const decimalNumber = 0.5;
+
 function convertToPercentage(decimalNumber) {
-  const decimalNumber = 0.5;
   const percentage = `${decimalNumber * 100}%`;
 
   return percentage;
 }
 
 console.log(decimalNumber);
-
-// =============> write your explanation here
-
-// Finally, correct the code to fix the problem
-// =============> write your new code here
+console.log(convertToPercentage(decimalNumber));
diff --git a/Sprint-2/1-key-errors/2.js b/Sprint-2/1-key-errors/2.js
@@ -4,17 +4,31 @@
 // this function should square any number but instead we're going to get an error
 
 // =============> write your prediction of the error here
+//
+// We have function declaration errors:
+// 1. Instead of a parameter there is an numeric value in the function signature
+// 2. We try to use undeclared variable num in the body of the function.
 
-function square(3) {
-    return num * num;
-}
+// function square(3) {
+//     return num * num;
+// }
 
 // =============> write the error message here
-
+//
+// SyntaxError: Unexpected number
+//
 // =============> explain this error message here
-
+//
+// As predicted error is a numeric literal instead of the function parameter.
+//
 // Finally, correct the code to fix the problem
-
+//
+// We need to change the number 3 with name of variable is used in function
+//
 // =============> write your new code here
 
+function square(num) {
+    return num * num;
+}
 
+console.log(square(3));
diff --git a/Sprint-2/2-mandatory-debug/0.js b/Sprint-2/2-mandatory-debug/0.js
@@ -2,13 +2,28 @@
 
 // =============> write your prediction here
 
-function multiply(a, b) {
-  console.log(a * b);
-}
+// In function multiply first will be evaluated the multiply expression in parentheses.
+// Then the received value will be printed in the console. So as result of running code
+// we'll get result output:
+// 320
+// The result of multiplying 10 and 32 is undefined
 
-console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
+// 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
 
+// The multiply(a, b) function doesn't have a return value. So every time we run
+// it we'll get undefined as a return value.
+
 // 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)}`);
diff --git a/Sprint-2/2-mandatory-debug/1.js b/Sprint-2/2-mandatory-debug/1.js
@@ -1,13 +1,27 @@
 // Predict and explain first...
 //  =============> write your prediction here
 
-function sum(a, b) {
-  return;
-  a + b;
-}
+// As the result of function's work we'll get undefined value. So th code running
+// result will look like:
+// 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)}`);
+// console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
 
 // =============> write your explanation here
+
+// It happens because function's return statement stands before summing expression
+// and return as function's work result undefined value.
+
 // 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)}`);
diff --git a/Sprint-2/2-mandatory-debug/2.js b/Sprint-2/2-mandatory-debug/2.js
@@ -3,22 +3,46 @@
 // Predict the output of the following code:
 // =============> Write your prediction here
 
-const num = 103;
+// The output will looks lke:
+// The last digit of 42 is 3
+// The last digit of 105 is 3
+// The last digit of 806 is 3
 
-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 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 given function doesn't have arguments and every time operate with variable
+// num that is declared as global and is initialized with value 103.
+
 // Finally, correct the code to fix the problem
 // =============> write your new code here
 
+const num = 103;
+
+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
diff --git a/Sprint-2/3-mandatory-implement/1-bmi.js b/Sprint-2/3-mandatory-implement/1-bmi.js
@@ -15,5 +15,5 @@
 // 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
+    return (weight / Math.pow(height, 2)).toFixed(1);
 }
diff --git a/Sprint-2/3-mandatory-implement/2-cases.js b/Sprint-2/3-mandatory-implement/2-cases.js
@@ -14,3 +14,7 @@
 // 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(' ', '_'); 
+}
diff --git a/Sprint-2/3-mandatory-implement/3-to-pounds.js b/Sprint-2/3-mandatory-implement/3-to-pounds.js
@@ -4,3 +4,86 @@
 // 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
+
+function toPounds(penceString) {
+  const paddedPenceNumberString = penceString.substring(0, penceString.length - 1).padStart(3, '0');
+
+  return `£${paddedPenceNumberString.substring(0, paddedPenceNumberString.length -2)}.${
+    paddedPenceNumberString.substring(paddedPenceNumberString.length - 2).padEnd(2, '0')}`;
+}
+
+let currentOutput = toPounds("0p");
+let targetOutput = '£0.00';
+console.assert(currentOutput === targetOutput, 
+  `Current output: '${currentOutput}', target output '${targetOutput}'`
+)
+
+currentOutput = toPounds("3p");
+targetOutput = "£0.03";
+console.assert(
+  currentOutput === targetOutput,
+  `Current output: '${currentOutput}', target output '${targetOutput}'`
+);
+
+currentOutput = toPounds("20p");
+targetOutput = "£0.20";
+console.assert(
+  currentOutput === targetOutput,
+  `Current output: '${currentOutput}', target output '${targetOutput}'`
+);
+
+currentOutput = toPounds("99p");
+targetOutput = "£0.99";
+console.assert(
+  currentOutput === targetOutput,
+  `Current output: '${currentOutput}', target output '${targetOutput}'`
+);
+
+currentOutput = toPounds("100p");
+targetOutput = "£1.00";
+console.assert(
+  currentOutput === targetOutput,
+  `Current output: '${currentOutput}', target output '${targetOutput}'`
+);
+
+currentOutput = toPounds("101p");
+targetOutput = "£1.01";
+console.assert(
+  currentOutput === targetOutput,
+  `Current output: '${currentOutput}', target output '${targetOutput}'`
+);
+
+currentOutput = toPounds("120p");
+targetOutput = "£1.20";
+console.assert(
+  currentOutput === targetOutput,
+  `Current output: '${currentOutput}', target output '${targetOutput}'`
+);
+
+currentOutput = toPounds("543p");
+targetOutput = "£5.43";
+console.assert(
+  currentOutput === targetOutput,
+  `Current output: '${currentOutput}', target output '${targetOutput}'`
+);
+
+currentOutput = toPounds("999p");
+targetOutput = "£9.99";
+console.assert(
+  currentOutput === targetOutput,
+  `Current output: '${currentOutput}', target output '${targetOutput}'`
+);
+
+currentOutput = toPounds("1000p");
+targetOutput = "£10.00";
+console.assert(
+  currentOutput === targetOutput,
+  `Current output: '${currentOutput}', target output '${targetOutput}'`
+);
+
+currentOutput = toPounds("1001p");
+targetOutput = "£10.01";
+console.assert(
+  currentOutput === targetOutput,
+  `Current output: '${currentOutput}', target output '${targetOutput}'`
+);
diff --git a/Sprint-2/4-mandatory-interpret/time-format.js b/Sprint-2/4-mandatory-interpret/time-format.js
@@ -19,16 +19,32 @@ function formatTimeDisplay(seconds) {
 // a) When formatTimeDisplay is called how many times will pad be called?
 // =============> write your answer here
 
+// The function pad(num) will be called 3 times in line 11.
+
+
 // Call formatTimeDisplay with an input of 61, now answer the following:
 
+formatTimeDisplay(61);
+
 // b) What is the value assigned to num when pad is called for the first time?
 // =============> write your answer here
 
+// num = 1;
+
+
 // c) What is the return value of pad is called for the first time?
 // =============> write your answer here
 
+// return value = '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
 
+// num = 1
+
+
 // 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
+
+// return value == '01'