Cape Town | 26-ITP-Sept | Leigh Ross | Sprint 2 | Complete Sprint 2 Coursework

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

@@ -4,3 +4,5 @@ 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
+
+// count is being increased each time the code runs by +1. = is basically just reassigning the value each time.

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

@@ -5,6 +5,12 @@ const 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.
 
-const initials = ``;
+const firstChar = firstName.charAt(0);
+const secondChar = middleName.charAt(0);
+const thirdChar = lastName.charAt(0);
+
+
+const initials = `${firstChar}${secondChar}${thirdChar}`;
+console.log(initials)
 
 // https://www.google.com/search?q=get+first+character+of+string+mdn

Sprint-2/1-key-exercises/3-paths.js

@@ -17,7 +17,12 @@ 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 ext = filePath.slice(filePath.lastIndexOf("."), filePath.length);
+
+console.log(dir)
+console.log(ext)
 
 // https://www.google.com/search?q=slice+mdn

Sprint-2/1-key-exercises/4-random.js

@@ -1,9 +1,18 @@
 const minimum = 1;
 const maximum = 100;
 
-const num = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum;
-
+const num = Math.floor(0.9185141991554047 * (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.floor() - rounds down to nearest integer
+// Math.random() - gives a random number between [0,1)
+// (max - min + 1) - 100
+// simple bodmas
+
+// example 
+// math.random() =  0.9185141991554047
+// num = 92

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

@@ -1,2 +1,4 @@
-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?
+
+// Comment out lines with "//"

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

@@ -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;
+// changed const to let

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

@@ -1,5 +1,7 @@
 // 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}`);
+
+// You must first assign the var before u try to print it

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

@@ -1,4 +1,4 @@
-const cardNumber = 4533787178994213;
+const cardNumber = "4533787178994213";
 const last4Digits = cardNumber.slice(-4);
 
 // The last4Digits variable should store the last 4 digits of cardNumber
@@ -7,3 +7,5 @@ const last4Digits = cardNumber.slice(-4);
 // 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
+console.log(last4Digits)
+// cardNumber was stored as a number, which does not work with .splice(). 

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

@@ -1,2 +1,3 @@
-const 12HourClockTime = "8:53pm";
-const 24hourClockTime = "20:53";
+const twelveHourClockTime = "8:53pm";
+const miliataryhourClockTime = "20:53";
+// variables cannot start with a number.

Sprint-2/3-mandatory-interpret/1-percentage-change.js

@@ -1,8 +1,8 @@
 let carPrice = "10,000";
 let priceAfterOneYear = "8,543";
 
-carPrice = Number(carPrice.replaceAll(",", ""));
-priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ""));
+carPrice = Number(carPrice.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
+// Number() line 4,5. .replaceAll() line 4,5. console.log() line 10.
 
 // 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: put a comma between the two arguments representing find and replace.
 
 // c) Identify all the lines that are variable reassignment statements
+// line 4, 5.
 
 // d) Identify all the lines that are variable declarations
+// line 1,2,7,8.
 
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+// convert str to number type and find and replace commas with nothing so that the number is read correctly.

Sprint-2/3-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?
+// 6
 
 // b) How many function calls are there?
+// 1
 
 // c) Using documentation, explain what the expression movieLength % 60 represents
 // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators
+// its a rem calculation, basically taking how many groups of 60 are in the movie, and giving back the remainder.
 
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
+// (movieLength - remainingSeconds): gives us a value that's an exact multiple of 60, so it divides evenly.
+// / 60: takes the whole number and converts it to minutes
 
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
+// the movie length in hours, minutes and seconds. formattedDuration
 
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+// edge cases: negative movie length. For negative movie lengths it should print an error saying that movielength cannot be less than 0.
+// : decimal numbers
+// : should tell user that the unit is seconds

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

@@ -25,3 +25,10 @@ console.log(`£${pounds}.${pence}`);
 
 // To begin, we can start with
 // 1. const penceString = "399p": initialises a string variable with the value "399p"
+// 2. const penceStringWithoutTrailingP: from index 0, to length of string - 1 (4-1=3). (0,3) we get the string from index 0 to index 2 which removes the p at the end.
+// 3. const paddedPenceNumberString: if length < 3, pad start of string with "0". since it is we just get 399.
+// 4. const pounds: take string from index 0 to length of string - 2 (3-2=1). (0,1) we get the 1st index "3".
+// 5. .substring(): length = 3. (3-2=1). (1,end of string). this gives us 99
+// 6. .padEnd(): if previous length of string < 2: pad end with "0"
+// 7. console.log() basically just prints pounds and pence as the proper format (£"pound"."pence") using string literals
+// NB: padding is for a safety measure if the inputs were shorter.

Sprint-2/4-stretch-explore/chrome.md

@@ -9,7 +9,24 @@ In the Chrome console, invoke the function `alert` with one argument, the string
 
 What effect does calling the `alert` function have?
 
+// Alert brings a pop up window out and says "Hello world" from the page. It also has a button called "OK"
+
 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`?
+
+// Opens a popup box with a text input. The value inside the () is what would display above the input.
+// The return value is myname in this case.
+// In general, prompt will store a string containing whatever the user typed or null if they clicked cancel.
+
+This is the code I did.
+alert("Hello world")
+undefined
+prompt("What is your name")
+'Tylerluvslasagne'
+let myname = prompt("what is your name")
+undefined
+console.log(myname)
+VM319:1 I LOVE MY EX
+undefined

Sprint-2/4-stretch-explore/objects.md

@@ -13,4 +13,18 @@ Try also entering `typeof console`
 Answer the following questions:
 
 What does `console` store?
+// Console is an object that stores properties as fucntions. (Think of import = math, math.sqrt(9))
+
 What does the syntax `console.log` or `console.assert` mean? In particular, what does the `.` mean?
+// It means that you are calling on console to run this particular function in your javascript code.
+// console.log: access property(log) inside object(console).
+// The . is the property access operator.
+// The () contain an argument(s) which run the code.
+
+My code:
+console.log
+    ƒ log() { [native code] }
+console
+    console {debug: ƒ, error: ƒ, info: ƒ, log: ƒ, warn: ƒ, …}
+typeof console
+    'object'