London | 26-ITP-May | Martin Mwaka | Sprint 2 | Coursework Exercises

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

@@ -1,13 +1,21 @@
 // Predict and explain first...
 //  =============> write your prediction here
+// Martin response - I predict that if I call this function with a spring parameter, it will return the string with the first letter capitalised
 
 // 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;
+// }
 
 // =============> write your explanation here
+// Martin response - this error is because str is name of the parameter for this function, and it is re-declared again inside the function
+
 // =============> write your new code here
+function capitalise(str) {
+  return `${str[0].toUpperCase()}${str.slice(1)}`;
+}
+
+console.log(capitalise("martin"));

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

@@ -2,19 +2,27 @@
 
 // Why will an error occur when this program runs?
 // =============> write your prediction here
+// Martin response - an error will occur because the variable decimalNumber is called without being declared in the global scope.  There is also a secondary error in that the parameter for convertToPercentage function is decimalNumber which is re-declared inside the function
 
 // Try playing computer with the example to work out what is going on
 
-function convertToPercentage(decimalNumber) {
-  const decimalNumber = 0.5;
-  const percentage = `${decimalNumber * 100}%`;
+// function convertToPercentage(decimalNumber) {
+//   const decimalNumber = 0.5;
+//   const percentage = `${decimalNumber * 100}%`;
 
-  return percentage;
-}
+//   return percentage;
+// }
 
-console.log(decimalNumber);
+// console.log(decimalNumber);
 
 // =============> write your explanation here
+// Martin response - the cause of the error is the parameter for convertToPercentage function is decimalNumber which is re-declared inside the function
 
 // Finally, correct the code to fix the problem
 // =============> write your new code here
+
+function convertToPercentage(decimalNumber) {
+  return `${decimalNumber * 100}%`;
+}
+
+console.log(convertToPercentage(0.5));

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

@@ -1,20 +1,24 @@
-
 // Predict and explain first BEFORE you run any code...
 
 // this function should square any number but instead we're going to get an error
 
 // =============> write your prediction of the error here
+// Martin response - the error is caused by the fact that a number (3) has been entered directly in place of a parameter (num) for the function
 
-function square(3) {
-    return num * num;
-}
+// function square(3) {
+//     return num * num;
+// }
 
 // =============> write the error message here
-
+// Martin response - error message is - "SyntaxError: Unexpected number"
 // =============> explain this error message here
 
 // Finally, correct the code to fix the problem
 
 // =============> write your new code here
 
+function square(num) {
+  return num * num;
+}
 
+console.log(square(3));

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

@@ -1,14 +1,22 @@
 // Predict and explain first...
 
 // =============> write your prediction here
+// Martin response - the function call will return undefined as there is no return value in the multiply function
 
 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
+// Martin response - the parameters a and b are multiplied and logged inside the function, but there is no return value so the return value from the function is undefined
 
 // 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-2/2-mandatory-debug/1.js

@@ -1,13 +1,21 @@
 // Predict and explain first...
 //  =============> write your prediction here
+// Martin response - I expect this to return a blank value as there is a return statement, with no expression;
 
 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
+// Martin response - the value returned is undefined because the return statement is return with no expression;
 // 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

@@ -2,23 +2,37 @@
 
 // Predict the output of the following code:
 // =============> Write your prediction here
+// Martin response - I predict the return value will be the last digit of num returned as a string
 
 const num = 103;
 
 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)}`);
+// 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
 // Explain why the output is the way it is
+// Martin response - the output is always 3.  The function does not take a parameter and the variable declared in the global scope, num, is called repeatedly inside the function.
+
 // =============> write your explanation here
+// Martin response - The function does not take a parameter, although the function calls include a parameter.  The variable in the global scope, num, is being called repeatedly within the function and this is why all function calls return the string value of 3
+
 // Finally, correct the code to fix the problem
 // =============> write your new code here
 
 // This program should tell the user the last digit of each number.
 // Explain why getLastDigit is not working properly - correct the problem
+// Martin response - my explanation is above
+
+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)}`);

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

@@ -15,5 +15,12 @@
 // 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 the BMI of someone based off their weight and height
+  const heightSquared = Number((height * height).toFixed(2));
+  const bmi = Number(weight / heightSquared).toFixed(1);
+  return bmi;
+}
+
+console.log(calculateBMI(70, 1.73));
+console.log(calculateBMI(90, 1.99));
+console.log(calculateBMI(80, 1.68));

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

@@ -14,3 +14,10 @@
 // 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 convertToUpperSnakeCase(str) {
+  return str.toUpperCase().split(" ").join("_");
+}
+
+console.log(convertToUpperSnakeCase("hello there"));
+console.log(convertToUpperSnakeCase("Lord of the rings"));

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

@@ -4,3 +4,13 @@
 // 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(pence) {
+  const value = pence / 100;
+  return `£${(pence / 100).toFixed(2)}`;
+}
+
+console.log(toPounds(399));
+console.log(toPounds(29));
+console.log(toPounds(3000));
+console.log(toPounds(5000000));

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

@@ -22,17 +22,22 @@ function formatTimeDisplay(seconds) {
 
 // a) When formatTimeDisplay is called how many times will pad be called?
 // =============> write your answer here
+// Martin response - pad will be called 3 times
 
 // Call formatTimeDisplay with an input of 61, now answer the following:
 
 // b) What is the value assigned to num when pad is called for the first time?
 // =============> write your answer here
+// Martin response - the value assigned to num when pad is called for the first time is 0
 
 // c) What is the return value of pad is called for the first time?
 // =============> write your answer here
+// Martin response - the return value of pad is called for the first time is "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
+// Martin response - the value assigned to num when it is called for the last time in this programme is 1
 
 // e) What is the return value of pad when it is called for the last time in this program?  Explain your answer
 // =============> write your answer here
+// Martin response - the return value of pad is called for the last time in this programme is "01"