Glasgow | 26-Jan-ITP | Alasdair MacDonald | Sprint 2 | coursework/sprint-2

Sprint-1/1-key-exercises/1-count.js

@@ -4,3 +4,4 @@ count = count + 1;
 
 // Line 1 is a variable declaration, creating the count variable with an initial value of 0
 // Describe what line 3 is doing, in particular focus on what = is doing
+// Line 3 reassigns the variable count by taking its current value, adding 1 to it, and storing the new value back into count. The = operator assigns the value on the right to the variable on the left.

Sprint-1/1-key-exercises/2-initials.js

@@ -5,7 +5,8 @@ let lastName = "Johnson";
 // Declare a variable called initials that stores the first character of each string.
 // This should produce the string "CKJ", but you must not write the characters C, K, or J in the code of your solution.
 
-let initials = ``;
+let initials = firstName[0] + middleName[0] + lastName[0];
 
 // https://www.google.com/search?q=get+first+character+of+string+mdn
 
+console.log(initials);

Sprint-1/1-key-exercises/3-paths.js

@@ -17,7 +17,9 @@ console.log(`The base part of ${filePath} is ${base}`);
 // Create a variable to store the dir part of the filePath variable
 // Create a variable to store the ext part of the variable
 
-const dir = ;
-const ext = ;
+const dir = filePath.slice(0, lastSlashIndex);
+
+const lastDotIndex = base.lastIndexOf(".");
+const ext = base.slice(lastDotIndex + 1);
 
 // https://www.google.com/search?q=slice+mdn

Sprint-1/1-key-exercises/4-random.js

@@ -3,7 +3,15 @@ const maximum = 100;
 
 const num = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum;
 
+console.log(num);
 // In this exercise, you will need to work out what num represents?
 // Try breaking down the expression and using documentation to explain what it means
 // It will help to think about the order in which expressions are evaluated
 // Try logging the value of num and running the program several times to build an idea of what the program is doing
+
+// Math.random https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/random
+// Math.floor https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/floor
+// mdn order of operations javascript https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Operator_precedence
+
+
+// It generates a random whole number between 1 and 100

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

@@ -1,2 +1,2 @@
-This is just an instruction for the first activity - but it is just for human consumption
-We don't want the computer to run these 2 lines - how can we solve this problem?
+// This is just an instruction for the first activity - but it is just for human consumption
+// We don't want the computer to run these 2 lines - how can we solve this problem?

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

@@ -1,4 +1,10 @@
 // trying to create an age variable and then reassign the value by 1
 
-const age = 33;
+let age = 33;
 age = age + 1;
+
+console.log(age);
+
+// Another way to write this code...
+// let age = 33;
+// age++;

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

@@ -1,5 +1,8 @@
 // Currently trying to print the string "I was born in Bolton" but it isn't working...
 // what's the error ?
 
-console.log(`I was born in ${cityOfBirth}`);
 const cityOfBirth = "Bolton";
+console.log(`I was born in ${cityOfBirth}`);
+
+
+// The variable was declared after console.log

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

@@ -1,9 +1,13 @@
 const cardNumber = 4533787178994213;
-const last4Digits = cardNumber.slice(-4);
+const last4Digits = cardNumber.toString().slice(-4);
+
+console.log(last4Digits);
 
 // The last4Digits variable should store the last 4 digits of cardNumber
 // However, the code isn't working
 // Before running the code, make and explain a prediction about why the code won't work
 // Then run the code and see what error it gives.
 // Consider: Why does it give this error? Is this what I predicted? If not, what's different?
 // Then try updating the expression last4Digits is assigned to, in order to get the correct value
+
+// This won't work because cardNumbers is a number, and numbers don't have the .slice() method.

Sprint-1/2-mandatory-errors/4.js

@@ -1,2 +1,5 @@
-const 12HourClockTime = "20:53";
-const 24hourClockTime = "08:53";
+const twelveHourClockTime = "20:53";
+const twentyFourHourClockTime = "08:53";
+
+console.log(twelveHourClockTime);
+console.log(twentyFourHourClockTime);

Sprint-1/3-mandatory-interpret/1-percentage-change.js

@@ -2,7 +2,7 @@ let carPrice = "10,000";
 let priceAfterOneYear = "8,543";
 
 carPrice = Number(carPrice.replaceAll(",", ""));
-priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ""));
+priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", ""));
 
 const priceDifference = carPrice - priceAfterOneYear;
 const percentageChange = (priceDifference / carPrice) * 100;
@@ -12,11 +12,16 @@ console.log(`The percentage change is ${percentageChange}`);
 // Read the code and then answer the questions below
 
 // a) How many function calls are there in this file? Write down all the lines where a function call is made
+// There is 5 function calls, anything that has () afterwards is a function. 
 
 // b) Run the code and identify the line where the error is coming from - why is this error occurring? How can you fix this problem?
+// I added a a comma , here --> (priceAfterOneYear.replaceAll(",", "")); as this was missing, I seen this as soon as i opened this exercise.
 
 // c) Identify all the lines that are variable reassignment statements
+// Lines 4 and 5 are reassignments, carPrice was declared with let and priceAfterOneYear was already declared with let.
 
 // d) Identify all the lines that are variable declarations
+// There is 4 declarations in total, theres where all varibales crated using let,const and var. (lines 1,2,7,8)
 
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+// breaking it down this part, carPrice.replaceAll(",", "") removes all commas from the string. Next step is this Number("10000"), this converts the string into a number.

Sprint-1/3-mandatory-interpret/2-time-format.js

@@ -12,14 +12,23 @@ console.log(result);
 // For the piece of code above, read the code and then answer the following questions
 
 // a) How many variable declarations are there in this program?
+// There is 6 variable declarations in this program. 
 
 // b) How many function calls are there?
+// There is 1 function call. console.log();
 
 // c) Using documentation, explain what the expression movieLength % 60 represents
 // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators
+// This means divide movieLength  by 60 and return what is left over.
+
 
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
+// Subtract the leftover seconds and divide by 60 so this calculates the total number of full minutes in the movie.
 
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
+// This builds a formatted string that looks like hours:minutes:seconds so the movie duration converted in time format (HH:MM:SS)
+// Result is quite vague a better variable name could be formattedTime 
 
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+// This works for positive whole numbers and any length in seconds.
+// It doesn't work handling negative numbers properly.

Sprint-1/3-mandatory-interpret/3-to-pounds.js

@@ -25,3 +25,17 @@ console.log(`£${pounds}.${pence}`);
 
 // To begin, we can start with
 // 1. const penceString = "399p": initialises a string variable with the value "399p"
+// 2. penceString.length gives the length of "399p" -> 4, length -1 = 3, substring(0,3) takes characters from idex 0 up to (but not including) index 3
+// 3. padStart(3, "0") ensures the string is at least 3 characters long.
+// 4. const pounds = paddedPenceNumberString.substring(
+// 0,
+//  paddedPenceNumberString.length - 2
+// );
+// What this does: it takes everything except the last 2 digits. Because: The last 2 digits represent pence and everything before that represents pounds.
+// 5.  substring(length - 2) --> takes the last 2 digits, .padEnd(2, "0") ensures it is always 2 digits.
+// 6. console.log() --> builds a formatted currency string £3.99
+
+// This program is doing overall, removing the "p", 
+// ensuring there are at least 3 digits, 
+// splitting the number into pounds and pence,
+// finally formatting it into a proper currency format.

Sprint-1/4-stretch-explore/chrome.md

@@ -16,3 +16,8 @@ Now try invoking the function `prompt` with a string input of `"What is your nam
 
 What effect does calling the `prompt` function have?
 What is the return value of `prompt`?
+
+// The returned value of prompt --> The string I typed or null if I press cancel.
+I typed Alasdair and when I called myName it was stored inside that variiable called myName.
+
+let myName = prompt("What is your name?");

Sprint-1/4-stretch-explore/objects.md

@@ -14,3 +14,6 @@ Answer the following questions:
 
 What does `console` store?
 What does the syntax `console.log` or `console.assert` mean? In particular, what does the `.` mean?
+
+
+Typing console.log shows a function definition (e.g. ƒ log() { [native code] }). This means console.log is a built-in function provided by the browser.

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

@@ -1,13 +1,19 @@
 // Predict and explain first...
 //  =============> write your prediction here
+// I think that the first letter of the string will be upper case and then the .slice method will extract a part of a string and return the extracted part, being --> apitalise.
 
 // call the function capitalise with a string input
 // interpret the error message and figure out why an error is occurring
+// function capitalise is already a variable and let str is decalring that variable again but str already exists.
 
-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
 // =============> write your new code here
+
+function capitalise(str) {
+  return `${str[0].toUpperCase()}${str.slice(1)}`;
+}

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

@@ -2,19 +2,28 @@
 
 // Why will an error occur when this program runs?
 // =============> write your prediction here
+// You cannot re-declare decimalNumber, it already exists as a parameter.
 
 // 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
+// We have to remove the re-declaration and pass a value into the function, then log the result of the fucntion.
 
 // 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 +1,23 @@
 
-// Predict and explain first BEFORE you run any code...
-
+// 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
+// You cannot put a number as a function parameter name
 
-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 "Unexpected number" error arises when a numeral is improperly positioned or used within your JavaScript code.
 // 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

@@ -1,14 +1,21 @@
 // Predict and explain first...
 
 // =============> write your prediction here
+// the first console.log cant be there as it has to be a return.
 
-function multiply(a, b) {
-  console.log(a * b);
-}
+// 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
-
+// It prints the number 320 in the terminal then 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 +1,20 @@
 // Predict and explain first...
 //  =============> write your prediction here
+// after the return it exists the function so it ever reaches a + b.
+//function sum(a, b) {
+  //return;
+  //a + b;
+//}
 
-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
+// however it did still , print The sum of 10 and 32 is undefined
 // 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 +2,39 @@
 
 // Predict the output of the following code:
 // =============> Write your prediction here
+//  The function does not take a parameter.
+//const num = 103;
 
-const num = 103;
+//function getLastDigit() {
+  //return num.toString().slice(-1);
+//}
 
-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
+// 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
+// This happens because the functionn does not accept a parameter, it always uses the global variable num and the arguments passed in (42, 105, 806) are ignored.
 // 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
+// here is the output with the code corrects 
+// the last digit of 42 is 2
+//The last digit of 105 is 5
+//The last digit of 806 is 6

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

@@ -15,5 +15,6 @@
 // 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
+    const bmi = weight / (height * height);
+  return Number(bmi.toFixed(1));
 }