London|26-ITP-January|Alexandru Pocovnicu|Sprint 1|Coursework

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

@@ -1,6 +1,6 @@
 let count = 0;
 
-count = count + 1;
+count = count + 1; //it assigns the variable "count" the value of "count +1" which 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

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 = `${firstName.charAt(0)}${middleName.charAt(0)}${lastName.charAt(0)}`;
+
 
 // https://www.google.com/search?q=get+first+character+of+string+mdn
 

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

@@ -12,12 +12,15 @@
 const filePath = "/Users/mitch/cyf/Module-JS1/week-1/interpret/file.txt";
 const lastSlashIndex = filePath.lastIndexOf("/");
 const base = filePath.slice(lastSlashIndex + 1);
+
+
 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(lastDotIndex+1);
+
 
 // https://www.google.com/search?q=slice+mdn

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

@@ -2,6 +2,8 @@ const minimum = 1;
 const maximum = 100;
 
 const num = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum;
+//num represents a pseudorandom number, in this case between 1 and 100
+
 
 // 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

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

@@ -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?
+// by commenting them out

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

@@ -1,4 +1,4 @@
 // trying to create an age variable and then reassign the value by 1
-
-const age = 33;
+//the error occurred because the variable was declared with const instead of let 
+let age = 33;
 age = age + 1;

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

@@ -1,5 +1,6 @@
 // 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}`);
+// the error occurs because the variable was declared after the log
 const cityOfBirth = "Bolton";
+console.log(`I was born in ${cityOfBirth}`);

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

@@ -1,6 +1,12 @@
-const cardNumber = 4533787178994213;
+const cardNumber = "4533787178994213";
 const last4Digits = cardNumber.slice(-4);
 
+
+
+//it won't work because slice() works on strings and arrays not on numbers
+
+
+
 // 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

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

@@ -1,2 +1,3 @@
-const 12HourClockTime = "20:53";
-const 24hourClockTime = "08:53";
+const twelveHourClockTime = "20:53";
+const twentyFourHourClockTime = "08:53";
+//variable names can not start with numbers

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

@@ -2,21 +2,36 @@ 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;
 
 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 are 5 function calls :
+    // 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?
+    //the error appears on line 5 because of a missing coma between the arguments, fixed by adding a coma
 
 // c) Identify all the lines that are variable reassignment statements
+    // 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 get's rid of the coma and turns the string in to a number

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

@@ -1,4 +1,4 @@
-const movieLength = 8784; // length of movie in seconds
+const movieLength = 123.4; // length of movie in seconds
 
 const remainingSeconds = movieLength % 60;
 const totalMinutes = (movieLength - remainingSeconds) / 60;
@@ -12,14 +12,20 @@ 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
+    //represents the seconds left after all the seconds have been to minutes
 
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
+    //it represents the movie length converted to minutes without the remaining seconds  
 
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
-
+    //it represents the movie length formatted to hours minutes seconds, a better name would be formattedMovieLength
+
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+    //i have tried values between 0-123456789 and float numbers, it does seem to work work

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

@@ -11,17 +11,40 @@ const pounds = paddedPenceNumberString.substring(
   paddedPenceNumberString.length - 2
 );
 
-const pence = paddedPenceNumberString
-  .substring(paddedPenceNumberString.length - 2)
-  .padEnd(2, "0");
+const pence = paddedPenceNumberString.substring(paddedPenceNumberString.length - 2).padEnd(2, "0");
 
 console.log(`£${pounds}.${pence}`);
 
+
+
 // This program takes a string representing a price in pence
 // The program then builds up a string representing the price in pounds
 
 // You need to do a step-by-step breakdown of each line in this program
 // 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": initializes a string variable with the value "399p"
+
+//2. const penceStringWithoutTrailingP = penceString.substring(
+  //   0,
+  //   penceString.length - 1
+  // );
+  //initializes a string variable with the value "399" by removing the last character "p" from penceString
+
+//3.  const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");
+  //initializes a string variable with the value penceStringWithoutTrailingP, with a minimum length of 3 characters, if it happens to be shorter it will add a "0" at the beginning of the string for every character that is short
+
+//4.  const pounds = paddedPenceNumberString.substring(
+//   0,
+//   paddedPenceNumberString.length - 2
+// ); 
+  //initializes a string variable with the value of paddedPenceNumberString except the final 2 characters, thus extracting the pounds, in this case "3"
+
+//5.   const pence = paddedPenceNumberString
+// .substring(paddedPenceNumberString.length - 2)
+// .padEnd(2, "0")
+  //it extracts the last two characters (pence) from paddedPenceNumberString and it makes sure that there's always gonna be two by adding "0" at the end
+
+//6.  console.log(`£${pounds}.${pence}`);
+  //it logs £3.99

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

@@ -14,3 +14,5 @@ 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 stores an object
+The "." is used to access "console" properties