LONDON | ITP_MAY | Mirabel Adom | Module-Structuring-and-Testing-Data | Sprint-2

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

@@ -1,13 +1,17 @@
 // Predict and explain first...
-//  =============> write your prediction here
+// The code will produce an error.
 
 // call the function capitalise with a string input
-// interpret the error message and figure out why an error is occurring
+//The error message indicates that 'str' has already been declared: function capitalise(str) and  let str
 
 function capitalise(str) {
   let str = `${str[0].toUpperCase()}${str.slice(1)}`;
   return str;
 }
 
-// =============> write your explanation here
-// =============> write your new code here
+// =============> The error message indicates that 'str' has already been declared.
+// =============>
+function capitalise(str) {
+  let capitalisedStr = `${str[0].toUpperCase()}${str.slice(1)}`;
+  return capitalisedStr;
+}

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

@@ -1,20 +1,25 @@
 // Predict and explain first...
 
 // Why will an error occur when this program runs?
-// =============> write your prediction here
+// =============> An error code will occur because 'decimalNumber' has already been declared.
 
 // 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
+// =============> The original code didn't work because the variable name was reused and the value was printed outside the function.
 
 // 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 +1,20 @@
-
 // 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
+// =============> The code will produce an error because the function parameters must be variable names, instead of a value - in this case the error has occured because of 3.
 
-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
+// =============> The error message suggests that JavaScript requires a variable name rather than a number.
 
 // Finally, correct the code to fix the problem
 
-// =============> write your new code here
-
-
+// =============>
+function square(num) {
+  return num * num;
+}

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

@@ -1,6 +1,6 @@
 // Predict and explain first...
 
-// =============> write your prediction here
+//The code does not include a return statement which means that the output is undefined.
 
 function multiply(a, b) {
   console.log(a * b);
@@ -11,4 +11,8 @@ console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
 // =============> write your explanation here
 
 // 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

@@ -1,5 +1,5 @@
 // Predict and explain first...
-//  =============> write your prediction here
+//  The code is incorrect because there is a semi-colon in line 5 and prevent line 6 from running: return;
 
 function sum(a, b) {
   return;
@@ -8,6 +8,11 @@ function sum(a, b) {
 
 console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
 
-// =============> write your explanation here
+//The code below ensures that the function is defined. This can be achieved by removing the semi-colon in line 5 of the previous code.
+
 // 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 and explain first
+// The three calls will all return the value 3
 
 // Predict the output of the following code:
-// =============> Write your prediction here
+The last digit of 42 is 3
+The last digit of 105 is 3
+The last digit of 806 is 3
 
 const num = 103;
 
@@ -14,11 +17,23 @@ 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
-// Finally, correct the code to fix the problem
-// =============> write your new code here
+// the function always uses the constant num, which is set to 103, so it always returns '3'
 
+// Finally, correct the code to fix the problem
 // This program should tell the user the last digit of each number.
 // Explain why getLastDigit is not working properly - correct the problem
+function getLastDigit(n) {
+  return n.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)}`);
+
+// the function  always uses the constant num which is set to 10; it ignores other arguments and consistently returns "3", the last digit of 103
+

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

@@ -15,5 +15,9 @@
 // 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 = height * height;
+return `${(weight / heightSquared).toFixed(1)}`;
+
+//console.log(calculateBMI(85, 1.80));

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

@@ -14,3 +14,8 @@
 // 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(input) {
+  return input.toUpperCase().split(" ").join("_");
+}
+//console.log(convertToUpperSnakeCase("may the force be with you"));

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

@@ -4,3 +4,47 @@
 // 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";
+
+const penceStringWithoutTrailingP = penceString.substring(
+  0,
+  penceString.length - 1
+);
+
+const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");
+const pounds = paddedPenceNumberString.substring(
+  0,
+  paddedPenceNumberString.length - 2
+);
+
+const pence = paddedPenceNumberString
+  .substring(paddedPenceNumberString.length - 2)
+  .padEnd(2, "0");
+
+console.log(`£${pounds}.${pence}`);
+
+//Refactored code
+function toPounds(penceString) {
+  const penceStringWithoutTrailingP = penceString.substring(
+    0,
+    penceString.length - 1
+  );
+
+  const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");
+
+  const pounds = paddedPenceNumberString.substring(
+    0,
+    paddedPenceNumberString.length - 2
+  );
+
+  const pence = paddedPenceNumberString
+    .substring(paddedPenceNumberString.length - 2)
+    .padEnd(2, "0");
+
+  return `£${pounds}.${pence}`;
+}
+
+// console.log(toPounds("399p")); // £3.99
+// console.log(toPounds("99p"));  // £0.99
+// console.log(toPounds("5p"));   // £0.05

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

@@ -17,18 +17,20 @@ function formatTimeDisplay(seconds) {
 // Questions
 
 // a) When formatTimeDisplay is called how many times will pad be called?
-// =============> write your answer here
+// The pad function will be called three 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
+// 0
 
 // c) What is the return value of pad is called for the first time?
-// =============> write your answer here
+// "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
+// The value assigned to num is 1
+//pad(totalHours); // totalHours = 0
 
 // 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
+//In the pad function, since num is 1, the return value will be "01" (formatted to two digits).
+// The return value is "01".