London|25-ITP-September|Alexandru Pocovnicu|Sprint 1| Coursework

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
+//It assigns the variable"count" a new value of "count+1" which is "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 = ``;
+let initials = firstName.charAt(0)+middleName.charAt(0)+lastName.charAt(0);
+
+//or
+
+let initials=firstName[0]+middleName[0]+lastName[0]
+
+
 
 // https://www.google.com/search?q=get+first+character+of+string+mdn
 
+// I really can't understand any of the documentation from developer.mozilla

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(1,lastSlashIndex);
+
+const extPart=base.lastIndexOf(".")
+const ext = base.slice(extPart);
 
 // https://www.google.com/search?q=slice+mdn

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

@@ -4,6 +4,17 @@ 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?
+    //num represents a variable with the a random number as its value
+
 // Try breaking down the expression and using documentation to explain what it means
+    //Math.random() returns a pseudo random number that's >=0 and <1
+    //Math.floor() rounds down to the nearest integer
+
 // It will help to think about the order in which expressions are evaluated
+   //this first (maximum-minimum+1) then this Math.random()* then this Math.floor() then this +minimum
+
 // Try logging the value of num and running the program several times to build an idea of what the program is doing
+   //it returns a pseudo random number that's >=0 and <1
+
+
+console.log(num);

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 out the lines

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

@@ -2,3 +2,5 @@
 
 const age = 33;
 age = age + 1;
+//the "age" variable has been declared with a const and already assigned a value and it can not 
+// be reassigned another value because of the "const"

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

@@ -3,3 +3,4 @@
 
 console.log(`I was born in ${cityOfBirth}`);
 const cityOfBirth = "Bolton";
+//a variable needs to be declared before being initialized

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

@@ -1,9 +1,17 @@
-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
 // 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
+
+
+//prediction: it won't work because the value of cardNumber is a number and slice() is a string method
+const cardNumber = "4533787178994213";
+const last4Digits = cardNumber.slice(-4);
+console.log(last4Digits);

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

@@ -1,2 +1,7 @@
-const 12HourClockTime = "20:53";
-const 24hourClockTime = "08:53";
+// const 12HourClockTime = "20:53";
+// const 24hourClockTime = "08:53";
+
+//the name of a variable can not start with a number
+
+const twelveHourClockTime = "20:53";
+const twenty4hourClockTime = "08:53";

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 +12,17 @@ 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
+    // 5 function calls: Number(),replaceAll(),Number(),replaceAll(),console.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, there was no "," between arguments
 
 // c) Identify all the lines that are variable reassignment statements
+   //line4,line5
 
 // d) Identify all the lines that are variable declarations
+   //line1,line2,line7,line8
 
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+   //it replaces "," from the carPrice with an empty string, basically deleting the commas, and then turning the string "10000" 
+   // in to a number 10000

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

@@ -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 variable declarations
 
 // b) How many function calls are there?
+   //1 function call
 
 // c) Using documentation, explain what the expression movieLength % 60 represents
 // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators
+   //% it's the remainder operator and it tells us how many seconds are left out of a whole minute
 
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
+   //total time in minutes without the remaining seconds
 
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
+   //"Movie length"
 
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+   //it will work with all values as long as they are numbers,

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

@@ -1,15 +1,15 @@
-const penceString = "399p";
+const penceString = "399p";    
 
 const penceStringWithoutTrailingP = penceString.substring(
   0,
   penceString.length - 1
-);
+);   //399
 
-const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");
+const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0"); //399
 const pounds = paddedPenceNumberString.substring(
   0,
   paddedPenceNumberString.length - 2
-);
+);   //3
 
 const pence = paddedPenceNumberString
   .substring(paddedPenceNumberString.length - 2)
@@ -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"
+
+//2. const penceStringWithoutTrailingP = penceString.substring(
+//   0,
+//   penceString.length - 1
+// ); :   it creates a variable with the value "399" by eliminating the character at index penceString.length - 1
+
+//3.const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");:initialises a string variable of at least 3 characters, 
+// if it has les than 3 characters it adds 0 to make up for it
+
+//4.const pounds = paddedPenceNumberString.substring(
+  //0,
+//   paddedPenceNumberString.length - 2
+// );:initialises a string variable with the value of  paddedPenceNumberString except the last 2 characters
+
+//5.const pence = paddedPenceNumberString
+  // .substring(paddedPenceNumberString.length - 2)
+  // .padEnd(2, "0");: takes the last 2 characters from paddedPenceNumberString , it has to be 2 characters long if not it will add a 0 for 
+  // every missing character
+  //it adds a dot between pounds and pence and logs 3.99

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

@@ -15,4 +15,7 @@ What effect does calling the `alert` function have?
 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?
+It generates an input field
+
 What is the return value of `prompt`?
+whatever is introduced int hte input field

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

@@ -13,4 +13,7 @@ Try also entering `typeof console`
 Answer the following questions:
 
 What does `console` store?
+it stores properties
+
 What does the syntax `console.log` or `console.assert` mean? In particular, what does the `.` mean?
+the dot allows to access the properties of the object "console"