London | 26-Jan-ITP | Angela McLeary | Sprint 1|Coursework/sprint 1

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

@@ -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
+
+//Answer:
+//Line 3 re-assigns the value of count and declares a new value increasing count by 1

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

@@ -5,7 +5,14 @@ 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 = ``;
+//Answer:
+//Solution using charAt() a Javascript string method that returns a character's position, using template literal 
+// and toUpperCase to ensure it is capitalized.
+let initials = `${firstName.charAt(0)}${middleName.charAt(0)}${lastName.charAt(0)}`.toUpperCase();
+console.log(initials);
+
+//alternative solution using string indexing, template literal and toUppercase(to make sure it is capitalized)
+//let initials - `${firstName[0]}${middleName[0]}${lastName[0]}`.toUpperCase());
 
 // https://www.google.com/search?q=get+first+character+of+string+mdn
 

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

@@ -17,7 +17,19 @@ 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 = ;
+//Answer:
+//**where the file lives** 
+// It gives me everything from Index 0 to 
+// the last slash just before the filename.
+const dir = filePath.slice(0, lastSlashIndex); 
+console.log(dir);
+
+//Answer:
+//**what type of file**
+//Uses the the lastIndexOf method to look for the dot.
+//the dot is now index 0 so we start from index 1 onwards 
+// to get the file type.
+const ext = filePath.slice(filePath.lastIndexOf(".") + 1);
+console.log(ext);
 
 // https://www.google.com/search?q=slice+mdn

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

@@ -4,6 +4,23 @@ 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?
+//*Answer:
+//Number returns a random whole number between 1 and 100.
+
 // Try breaking down the expression and using documentation to explain what it means
+/*Answer:
+It uses 2 methods to achieve this
+Math.random generate a random number between 0 and 1 eg. 0.343, 0.5. 0.67
+Math.floor rounds the number to a whole number.
+In this declaration:
+Math.random will return a random decimal number and multiplies it by the sum of 
+((maximum-minimum)+1). eg 0.343_*((100-1)+1) = 34.3.
+Math.floor will take the total 34.3 and round it to a whole number 34*/
+
 // It will help to think about the order in which expressions are evaluated
+//*Answer:
+//it first works out the random decimal number calculates the other values then evaluates to sum to a whole number. 
+
 // Try logging the value of num and running the program several times to build an idea of what the program is doing
+//*Answer:
+//28, 64, 52, 86

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

@@ -1,2 +1,8 @@
-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?*/
+
+//*Answer
+// We comment it out,
+// We can do this by using a two forward slashes ("//")if it is on one line
+//or we use one forward slash with an asterisk at the start("/*") and an asterisk 
+// and a forward slash at the end ("*/") for block commenting

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

@@ -1,4 +1,11 @@
 // trying to create an age variable and then reassign the value by 1
 
-const age = 33;
+//const age = 33;
+//age = age + 1;
+
+//Answer:
+//we cannot re-assign variables with "const". 
+// We have use "let". let allows the variable to be re-assigned.
+let age = 33;
 age = age + 1;
+console.log(age);

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

@@ -1,5 +1,12 @@
 // 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}`);
+//console.log(`I was born in ${cityOfBirth}`);
+//const cityOfBirth = "Bolton";
+
+//*Answer
+// The console.log is before the variable and it cannot see it. 
+// The console log needs to be below the variable to compute the data.
+
 const cityOfBirth = "Bolton";
+console.log(`I was born in ${cityOfBirth}`);

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

@@ -1,9 +1,24 @@
-const cardNumber = 4533787178994213;
-const last4Digits = cardNumber.slice(-4);
+//const cardNumber = 4533787178994213;
+//const last4Digits = cardNumber.slice(-4);
 
 // 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
+//*Answer
+//It won't work because cardNumber is not a string and .slice() only works with strings. It will throw an error.
+
 // Then run the code and see what error it gives.
+//*Answer
+//Uncaught TypeError: cardNumber.slice is not a function
+
 // Consider: Why does it give this error? Is this what I predicted? If not, what's different?
+//*Answer
+//I was right. cardNumber is a number not a string and .slice() only works with strings 
+// so it needs to be converted to a string to work using .toString()
+
 // Then try updating the expression last4Digits is assigned to, in order to get the correct value
+//*Answer
+const cardNumber = 4533787178994213;
+const last4Digits = cardNumber.toString().slice(-4);
+console.log(last4Digits);

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

@@ -1,2 +1,11 @@
-const 12HourClockTime = "20:53";
-const 24hourClockTime = "08:53";
+//const 12HourClockTime = "20:53";
+//const 24hourClockTime = "08:53";
+
+//What's wrong with this code?
+//*Answer
+//The variable is not named in line with the Javascript naming convention. 
+// When declaring a variable it must not start with a number, space or reserved word.
+// to fix this, we can rename them correctly.
+
+const twelve_HourClockTime = "20:53";
+const twentyFour_HourClockTime = "08:53";

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

@@ -1,22 +1,47 @@
 let carPrice = "10,000";
 let priceAfterOneYear = "8,543";
 
-carPrice = Number(carPrice.replaceAll(",", ""));
-priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ""));
+carPrice = Number(carPrice.replaceAll(",", "")); // returns 10000
+priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",",""));//returns 8543
+//priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," "")); 
+// incorrect code missing syntax ie a comma
 
 const priceDifference = carPrice - priceAfterOneYear;
 const percentageChange = (priceDifference / carPrice) * 100;
 
-console.log(`The percentage change is ${percentageChange}`);
+console.log(`The percentage change is ${percentageChange}`); //returns The percentage change is 14.57
 
 // 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
+// a) How many function calls are there in this file? 
+// Write down all the lines where a function call is made
+//*Answer
+//There are 5 function calls: 2* Number(), 2*.replaceAll() and 1* console.log().
+//carPrice = Number(carPrice.replaceAll(",", ""));
+//priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",",""));
+//console.log(`The percentage change is ${percentageChange}`);
 
-// 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?
+// 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?
+//*Answer it is missing a comma on line 5.
+// Add the comma to fix it: ...replaceAll(",",""));
 
 // c) Identify all the lines that are variable reassignment statements
+//*Answer
+//carPrice = Number(carPrice.replaceAll(",", ""));
+//priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ""));
+
 
 // d) Identify all the lines that are variable declarations
+//let carPrice = "10,000";
+//let priceAfterOneYear = "8,543";
+//const priceDifference = carPrice - priceAfterOneYear;
+//const percentageChange = (priceDifference / carPrice) * 100;
+
+
+// e) Describe what the expression 
+// Number(carPrice.replaceAll(",","")) is doing - 
+// what is the purpose of this expression?
+//It converts the carPrice into a number and removes the spaces and commas.
+
 
-// e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?

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

@@ -12,14 +12,37 @@ 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?
+// *Answer
+// There are 6.
 
 // b) How many function calls are there?
+// *Answer 
+// There is 1; console.log()
 
 // c) Using documentation, explain what the expression movieLength % 60 represents
+//*Answer
+// This expression returns the remainder of seconds, after dividing the movieLength by 60, 
+// using the modulus operator it returns 24 seconds
 // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators
 
-// d) Interpret line 4, what does the expression assigned to totalMinutes mean?
-
-// e) What do you think the variable result represents? Can you think of a better name for this variable?
 
-// f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+// d) Interpret line 4, what does the expression assigned to totalMinutes mean?
+// *Answer
+// It is converting the seconds to minutes and rounding it to the last whole minute.
+
+// e) What do you think the variable result represents? 
+// *Answer
+// The result is the duration of the film in hours, minutes and seconds - 2:26:24.
+
+// Can you think of a better name for this variable?
+// *Answer
+//  movieDuration
+
+// f) Try experimenting with different values of movieLength. 
+// Will this code work for all values of movieLength? Explain your answer,
+// *Answer
+// I changed the value to;
+// 1200 returned 0:20:00
+// 92383.7 returned 25:39:43.69999999999709
+// -8784 returned -2:-26:-24
+// it worked with all numbers including decimals and negative numbers.

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

@@ -24,4 +24,34 @@ console.log(`£${pounds}.${pence}`);
 // Try and describe the purpose / rationale behind each step
 
 // To begin, we can start with
-// 1. const penceString = "399p": initialises a string variable with the value "399p"
+// 1. const penceString = "399p": initialises a string variable with the value "399p" 
+
+// 2. const penceStringWithoutTrailingP = penceString.substring(0, penceString.length - 1);
+//  This takes the variable penceString and uses the .substring() method to extract part of the string.
+//  It starts at index 0 and ends at penceString.length - 1, which removes the last character and
+//  outputs all characters except the trailing "p".
+//  This returns "399".
+
+// 3.const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");
+// This takes the value of the penceStringWithoutTrailingP and uses .padStart() method  to always return a minimum 
+// length of 3 characters. if the value computed is not a least 3 characters, it outputs leading 0's to make 
+// to make the string to 3 characters. If the string is 4 or more characters it just outputs the value without the leading 0's.
+// This returns "399". (examples: 45 returns 045, 1295 returns 1295)
+
+// 4.const pounds = paddedPenceNumberString.substring( 0, paddedPenceNumberString.length - 2);
+// This takes the value of paddedPenceNumberString and uses the .substring() method to extract the first art of the string.
+// It starts at index 0 and ends at paddedPenceNumberString.length - 2, which removes the last two characters.
+// This leaves the pounds portion of the value.
+// This returns "3". (examples: 45 returns 0, 1295 returns 12)
+
+// 5.const pence = paddedPenceNumberString.substring(paddedPenceNumberString.length - 2).padEnd(2, "0");
+// This takes the variable paddedPenceNumberString and extracts the last two characters using .substring(), 
+// which represent the pence. If the string is shorter than 2 characters, .padEnd(2, "0") adds trailing zeros 
+// to ensure the pence portion is always 2 digits.
+// This returns "99". (examples: 45 returns 45, 1295 returns 95)
+
+// 6. console.log(`£${pounds}.${pence}`);
+// console.log() outputs the formatted money value to the console. It uses a template literal (backticks) 
+// to embed the variables `pounds` and `pence` directly inside the string using ${} syntax.
+// The £ symbol is included at the start, and the dot separates pounds and pence.
+// This returns "£3.99" (examples: 45 returns £0.45, 1295 returns £12.95)

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

@@ -9,10 +9,18 @@ Let's try an example.
 
 In the Chrome console,
 invoke the function `alert` with an input string of `"Hello world!"`;
+alert('Hello World!');
 
 What effect does calling the `alert` function have?
+A pop up modal box appears with "Hello World!"
 
 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`.
+let myName = prompt("What is your name?");
 
 What effect does calling the `prompt` function have?
+It displays a modal dialog box with a text input field which can be completed.
+
 What is the return value of `prompt`?
+It is hidden, it does not display anything. The box closes.
+When I do a console.log(myName); it returns Angela.
+

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

@@ -5,12 +5,21 @@ In this activity, we'll explore some additional concepts that you'll encounter i
 Open the Chrome devtools Console, type in `console.log` and then hit enter
 
 What output do you get?
+ƒ log() { [native code] }
 
 Now enter just `console` in the Console, what output do you get back?
+console {debug: ƒ, error: ƒ, info: ƒ, log: ƒ, warn: ƒ, …}
 
 Try also entering `typeof console`
+'object'
 
 Answer the following questions:
 
 What does `console` store?
-What does the syntax `console.log` or `console.assert` mean? In particular, what does the `.` mean?
+It does not store anything. It's purpose is to hold a collection of methods (functions) that help you debug, log, or inspect your code.
+
+What does the syntax `console.log` or `console.assert` mean?,
+They print outputs.It provides methods for debugging, logging, and inspecting code.
+
+In particular, what does the `.` mean?
+The dot is a member access operator that connects the object to its property or method.