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3 changes: 3 additions & 0 deletions Sprint-1/1-key-exercises/1-count.js
Original file line number Diff line number Diff line change
Expand Up @@ -4,3 +4,6 @@ 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, we reassign a new value to the count variable,
// the new value is count plus 1.
Comment on lines +8 to +9

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Operation like count = count + 1 is very common in programming, and there is a programming term describing such operation.

Could you find out what one-word programming term describes the operation on line 3?

4 changes: 3 additions & 1 deletion Sprint-1/1-key-exercises/2-initials.js
Original file line number Diff line number Diff line change
Expand Up @@ -5,7 +5,9 @@ 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 = `${firstName.charAt(0)}${middleName.charAt(0)}${lastName.charAt(0)}`;
console.log(initials);


// https://www.google.com/search?q=get+first+character+of+string+mdn

6 changes: 3 additions & 3 deletions Sprint-1/1-key-exercises/3-paths.js
Original file line number Diff line number Diff line change
Expand Up @@ -16,8 +16,8 @@ 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(1, 16);
const ext = filePath.slice(-4);
console.log(`The base part of ${dir} is ${ext}`);
Comment on lines +19 to +21

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Could you make these statements to work for any valid path? For example, they could still work correctly if we changed line 12 to

const filePath = "/Users/jacknguyen448/cyf/Module-2/Sprint-1/package.json";


// https://www.google.com/search?q=slice+mdn
7 changes: 7 additions & 0 deletions Sprint-1/1-key-exercises/4-random.js
Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,13 @@ const maximum = 100;
const num = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum;

// In this exercise, you will need to work out what num represents?
console.log(Math.random())
console.log(num);
// 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
// num = Math.floor which will remove all the numbers after the decimal point

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Could you look up the differences among Math.round(), Math.trunc(), Math.floor(), Math.ceil()?
All of these functions remove the decimal part of a number, but in different manner.

// (Math.random that will generate a random decimal number
// which will be times with the value of maximum - minimum + 1 + minimum )
// which is 100 * the Math.random generated
Comment on lines +14 to +16

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Math.random() returns a random number within a range.

Could you describe what each of these expressions does, and the range of the numbers it may produce?

  1. Math.random()
  2. Math.random() * (maximum - minimum + 1)
  3. Math.floor(Math.random() * (maximum - minimum + 1))
  4. Math.floor(Math.random() * (maximum - minimum + 1)) + minimum

Note: To describe a range of numbers, we could use the math interval notation:

  • [, ] => inclusion
  • (, ) => exclusion

For example, [1, 10) means, all numbers between 1 and 10, including 1 but excluding 10.

5 changes: 3 additions & 2 deletions Sprint-1/2-mandatory-errors/0.js
Original file line number Diff line number Diff line change
@@ -1,2 +1,3 @@
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?
// need to use pseudo code
3 changes: 2 additions & 1 deletion Sprint-1/2-mandatory-errors/1.js
Original file line number Diff line number Diff line change
@@ -1,4 +1,5 @@
// trying to create an age variable and then reassign the value by 1

const age = 33;
let age = 33;
age = age + 1;
// const variable cannot reassign the value - we need to use let
5 changes: 4 additions & 1 deletion Sprint-1/2-mandatory-errors/2.js
Original file line number Diff line number Diff line change
@@ -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 cityOfBirth was after the console log which means you cannot log before you actually have the variable
7 changes: 6 additions & 1 deletion Sprint-1/2-mandatory-errors/3.js
Original file line number Diff line number Diff line change
@@ -1,9 +1,14 @@
const cardNumber = 4533787178994213;
const cardNumber = "4533787178994213";
const last4Digits = cardNumber.slice(-4);
Comment on lines +1 to 2

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Suppose you were not allowed to modify the statement const cardNumber = 4533787178994213;
(that is, keep the variable's value unchanged).
How would you modify the code (through type conversion) to still being able to use .slice(-4) to extract the last 4 digits from the given number.

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.
//const last4Digits = cardNumber.slice(-4);

// Consider: Why does it give this error? Is this what I predicted? If not, what's different?
// The error comes up cause the value of the cardNumber is not a string it's a number
//Once you change the value to a string the .slice()
// Then try updating the expression last4Digits is assigned to, in order to get the correct value
6 changes: 4 additions & 2 deletions Sprint-1/2-mandatory-errors/4.js
Original file line number Diff line number Diff line change
@@ -1,2 +1,4 @@
const 12HourClockTime = "8:53pm";
const 24hourClockTime = "20:53";
const twelveHourClockTime = "8:53pm";
const twentyFourHourClockTime = "20:53";

//we cannot start a variable name with a number
7 changes: 6 additions & 1 deletion Sprint-1/3-mandatory-interpret/1-percentage-change.js
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand All @@ -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 calls: 2* Number() 2* .replaceAll() AND 1* .log()

// 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?
// line 5 missing a comma: .replaceAll("," "")

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We could more precisely describe "A comma is missing between "," and "" in the function call" as:
A comma is missing between the ___________s.

What is this programming term that refers to the values passed to a function? It begins with an 'a'.


// c) Identify all the lines that are variable reassignment statements
// line 4 carPrice and line 5 priceAfterOneYear

// d) Identify all the lines that are variable declarations
// line 1 carPrice and line 2 priceAfterOneYear

// e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
//the Number() function converts the string value into number - however we cannot convert comma we would need to replace this with the .replaceAll() method
12 changes: 11 additions & 1 deletion Sprint-1/3-mandatory-interpret/2-time-format.js
Original file line number Diff line number Diff line change
@@ -1,4 +1,6 @@
const movieLength = 8784; // length of movie in seconds
let movieLength = 8784; // length of movie in seconds
movieLength = 9000;
movieLength = 6500;

const remainingSeconds = movieLength % 60;
const totalMinutes = (movieLength - remainingSeconds) / 60;
Expand All @@ -11,15 +13,23 @@ 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 declaration

// b) How many function calls are there?
// there is only the log() call

// c) Using documentation, explain what the expression movieLength % 60 represents
// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators
// the logic is to calculate the movieLength remainder - operator returns the remainder left over when one operand is divided by a second operand.
// It always takes the sign of the dividend.

// d) Interpret line 4, what does the expression assigned to totalMinutes mean?
// to calculate the movie length into minutes

// e) What do you think the variable result represents? Can you think of a better name for this variable?
// the result represent the movie length - hours minutes and second in a string - movieTime

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The name movieTime does not quite indicate the value stored in the variable
is a formatted string in the form "2:12:02".

Could you suggest a more descriptive name?


// f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
// Yes - the above logic calculates the movie length in hours minutes and seconds
19 changes: 19 additions & 0 deletions Sprint-1/3-mandatory-interpret/3-to-pounds.js
Original file line number Diff line number Diff line change
Expand Up @@ -25,3 +25,22 @@ console.log(`£${pounds}.${pence}`);

// To begin, we can start with
// 1. const penceString = "399p": initialises a string variable with the value "399p"
//
// 3.const penceStringWithoutTrailingP = penceString.substring(
// 0,
// penceString.length - 1
// ); assigned the string to a new variable with out the P - by using the substring method - the .length will count the number of the characters and only display 1 before last
//
// 8. const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");
// using the pedStart method we ensure to fill the gas - we can add 0 on this occasion to our string beginning the the number of length does not match with 3 characters - fill in the gaps
// 9. const pounds = paddedPenceNumberString.substring(
// 0,
// paddedPenceNumberString.length - 2
//); again we create a new variable to only store the first character of the string
//
// 14. const pence = paddedPenceNumberString
// .substring(paddedPenceNumberString.length - 2)
// .padEnd(2, "0");
// creating a new variable to assign only the last two character of the string - we also use the padEnd method to fill the end gaps with zeros
//
// 18. we call the newly created variables with consol.log to display this as a new string on the console
7 changes: 4 additions & 3 deletions Sprint-1/4-stretch-explore/chrome.md
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Expand Up @@ -10,9 +10,10 @@ Let's try an example.
In the Chrome console,
invoke the function `alert` with an input string of `"Hello world!"`;

What effect does calling the `alert` function have?
What effect does calling the `alert` function have? - alert is a pop up display message with an OK button - you can close once you click on the OK button

Now try invoking the function `prompt` with a string input of `"What is your name?"` - store the return value of your call to `prompt` in an variable called `myName`.

What effect does calling the `prompt` function have?
What is the return value of `prompt`?
What effect does calling the `prompt` function have? - the prompt will also display a message usually question - however this time you will have an empty field to enter the value or answer - a cancel and a OK button

What is the return value of `prompt`? - whatever the user inputs into the empty field

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What if the a enters something and then click "Cancel" instead of "OK?

11 changes: 9 additions & 2 deletions Sprint-1/4-stretch-explore/objects.md
Original file line number Diff line number Diff line change
Expand Up @@ -12,5 +12,12 @@ Try also entering `typeof console`

Answer the following questions:

What does `console` store?
What does the syntax `console.log` or `console.assert` mean? In particular, what does the `.` mean?
What does `console` store? - is an object of properies of methods

What does the syntax `console.log` or `console.assert` mean? In particular, what does the `.` mean?

* console.log() is call and display something on the terminal/console
* console.assert() checks if the condition is True or False
* the . is also called the dot notation - access something that belongs to an object - method is a function that stores inside a function


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