London | 26-ITP-Jan | Zadri Abdule | Sprint 2 | Coursework

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

@@ -1,5 +1,6 @@
 // Predict and explain first...
 //  =============> write your prediction here
+// It will show a error
 
 // call the function capitalise with a string input
 // interpret the error message and figure out why an error is occurring
@@ -8,6 +9,13 @@ function capitalise(str) {
   let str = `${str[0].toUpperCase()}${str.slice(1)}`;
   return str;
 }
+capitalise("Hello");
 
 // =============> write your explanation here
+// SyntaxError: Identifier 'str' has already been declared - This error means that the variable 'str' was declared more than once in the same scope.
+// JavaScrip doesn't allow that - once a variable name is declared with let or const, you can't declare it again.
 // =============> write your new code here
+function capitalise(str) {
+  return str[0].toUpperCase() + str.slice(1);
+}
+

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

@@ -2,6 +2,7 @@
 
 // Why will an error occur when this program runs?
 // =============> write your prediction here
+// I predict that this program will throw a error message  - due to the variable decimalNumber being redeclared
 
 // Try playing computer with the example to work out what is going on
 
@@ -15,6 +16,22 @@ function convertToPercentage(decimalNumber) {
 console.log(decimalNumber);
 
 // =============> write your explanation here
+// Function covertToPercentage(decimalNumber) - it has a parameter named decimalNumber
+// Inside the function: const decimalNumber = 0.5; - this redeclares the same variable name that's already used for the parameter.
+// That causes a error: SyntaxError: Identifier 'decimalNumber' has already been declared - because you can't declare a const (or let)
+// with the same name as a parameter inside the same function scope.
+// JavaScript doesn't allow us to declare a new variable with the same name in the same scope, so it caused a error
 
 // 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));
+
+// Function decimalNumber = 0.5
+// It calculates 0.5 * 100 = 50
+// It returns "50%"
+// console logs 50%

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

@@ -10,11 +10,16 @@ function square(3) {
 }
 
 // =============> write the error message here
-
+// SyntaxError: Unexpected number
 // =============> explain this error message here
-
+// The "Unexpected number"
 // Finally, correct the code to fix the problem
-
+// The "Unexpected number" error arises when a number is improperly positioned or used within JvaScript code
 // =============> write your new code here
+ function square(num){
+      return num * num;
+}
+
+console.log(square);
 
 

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

@@ -1,14 +1,20 @@
 // Predict and explain first...
 
 // =============> write your prediction here
-
+// It will show a undefined error 
 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
-
+// The function printed the answer but did't return it, so when it was used in the template string, it came out as '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 multipying 10 and 32 is ${multiply(10, 32)}`);
+

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

@@ -1,5 +1,6 @@
 // Predict and explain first...
 //  =============> write your prediction here
+// I predict it will show a undefined error
 
 function sum(a, b) {
   return;
@@ -9,5 +10,11 @@ function sum(a, b) {
 console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
 
 // =============> write your explanation here
+// The problem was the semicolon after return, which made the function stop before adding the numbers
 // Finally, correct the code to fix the problem
 //  =============> write your new code here
+function sum(a, b){
+  return a + b; // Once I put a + b on the same line as return, it worked
+}
+
+console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);

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

@@ -2,7 +2,7 @@
 
 // Predict the output of the following code:
 // =============> Write your prediction here
-
+// Since getLastDigit() does not declare any parameters, the arguments passed when calling it are going to be ignored
 const num = 103;
 
 function getLastDigit() {
@@ -15,10 +15,25 @@ 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 function getLastDigit() does not have any parameters, but it is being called with arguments:
+// getLastDigit(42), getLastDigit(105), and getLastDigit(806). Inside the function, it always uses the global const num, which is set to 103.
+// The means every call ignores the last digit of 103. Which the '3'
+
+
 // 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

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

@@ -16,4 +16,11 @@
 
 function calculateBMI(weight, height) {
     // return the BMI of someone based off their weight and height
-}
+    const bmi = weight / (height * height);
+    return bmi.toFixed(1);
+}
+
+console.log(`Your BMI is ${calculateBMI(68, 1.75)}`);
+// How it works: function calculateBMI(weight, height)
+// Parameters: weight - number, person's weight in kilograms height - number, person's height in meters 
+// Returns: the body mass index (BMI), rounded to one decimal place

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

@@ -14,3 +14,6 @@
 // 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
+const greeting = "Hello there."
+
+console.log(greeting.toUpperCase());

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 formatPenceToPounds(penceString){
+    const penceStringWithoutTrailingP = penceString.substring(0, penceString.length -1);
+    const pounds = paddedPenceNumberString.slice(0, -2);
+    const pence = paddedPenceNumberString.slice(-2);
+     return `£${pounds}.${pence}`;
+}
+
+console.log(formatPenceToPounds("9p"));
+console.log(formatPenceToPounds("39p"));
+console.log(formatPenceToPounds("399"));

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

@@ -18,17 +18,27 @@ function formatTimeDisplay(seconds) {
 
 // a) When formatTimeDisplay is called how many times will pad be called?
 // =============> write your answer here
+// 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
-
+/* The first time pad() run, its used for hours part of time.
+   Because 61 seconds equals 0 hours, the value given to num is 0. */
 // c) What is the return value of pad is called for the first time?
 // =============> write your answer here
+/* The first time pad() runs, it's formatting the hours part of time.
+Since the hours value is 0, it turns that into the string '00' by adding a leading zero before returning it. */
 
 // 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
+/* When the function runs with 61 seconds, the last time pad() is called is for the second part of the time.
+Since 61 seconds has 1 second left over after making a full minute, the value passed into pad() is 1.
+Inside the function, num equals 1, and it gets turned into '01' so the final time shows as 00:01:01. */
 
 // 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
+/* When pad() is called for the last time, num is 1 because there's 1 second left over.
+   The function turns that number into the string '01' by adding a leading zero.
+   That '01' is the value that gets returned and used as the seconds part of the final time display (00:01:01). */

Sprint-2/5-stretch-extend/format-time.js

@@ -2,7 +2,7 @@
 // Make sure to do the prep before you do the coursework
 // Your task is to write tests for as many different groups of input data or edge cases as you can, and fix any bugs you find.
 
-function formatAs12HourClock(time) {
+ /*function formatAs12HourClock(time) {
   const hours = Number(time.slice(0, 2));
   if (hours > 12) {
     return `${hours - 12}:00 pm`;
@@ -22,4 +22,55 @@ const targetOutput2 = "11:00 pm";
 console.assert(
   currentOutput2 === targetOutput2,
   `current output: ${currentOutput2}, target output: ${targetOutput2}`
+); */
+
+// The function ignores the minutes and did'not handle midnight (00:00) or noon (12:00) properly. 
+ // Better version:
+ function formatAs12HourClock(time) {
+  const hours = Number(time.slice(0, 2));
+  const minutes = time.slice(3, 5);
+
+  if (hours == 0) return `12:${minutes} am`; 
+  if (hours < 12) return `${time} am`;
+  if (hours === 12) return `${time} pm`;
+
+  return `${hours - 12}:${minutes} pm`;
+}
+const currentOutput1 = formatAs12HourClock("08:00");
+const targetOutput1 = "08:00 am";
+console.assert(
+  currentOutput1 === targetOutput1,
+  `current output: ${currentOutput1}, target output: ${targetOutput1}`
 );
+// Test failed: due to a typo
+const currentOutput2 = formatAs12HourClock("23:00");
+const targetOutput2 = "11:00 pm";
+console.assert(
+  currentOutput2 === targetOutput2,
+  `current output: ${currentOutput2}, target output: ${targetOutput2}`
+
+);
+
+const currentOutput3 = formatAs12HourClock("13:00");
+const targetOutput3 = "1:00 pm";
+console.assert(
+  currentOutput3 === targetOutput3,
+  `current output: ${currentOutput3} target output: {targetOutput3}`
+);
+
+const currentOutput4 = formatAs12HourClock("15:00");
+const targetOutput4 = "3:00 pm";
+console.assert(
+  currentOutput4 === targetOutput4,
+  `current output: ${currentOutput4} target output: {targetOutput4}`
+);
+
+console.log(formatAs12HourClock("08:00"));
+console.log(formatAs12HourClock("23:00"));
+console.log(formatAs12HourClock("15:00"));
+console.assert(formatAs12HourClock("00:00") === "12:00 am");
+console.assert(formatAs12HourClock("12:00") === "12:00 pm");
+
+// The test passed, so my function gave the expected results.
+// All the console.assert() tests passed.
+// formatAs12HourClock() function works correctly for the inputs I tested.