London | 26-ITP-Sep | Anita Amirhaeri | Sprint 2 | Coursework/sprint 2

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

@@ -3,4 +3,4 @@ let count = 0;
 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
+// Describe whaWt line 3 is doing, in particular focus on what = we calculate the value of sum operator and put it in left variable.

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

@@ -4,7 +4,11 @@ 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.
+let initials =
+  `${firstName.charAt(0)}` +
+  `${middleName.charAt(0)}` +
+  `${lastName.charAt(0)}`;
 
-const initials = ``;
+console.log(initials);
 
 // https://www.google.com/search?q=get+first+character+of+string+mdn

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

@@ -16,8 +16,9 @@ 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 = filePath.slice(0, lastSlashIndex);
+console.log(`The direction of the file is ${dir}`);
+const ext = filePath.slice(filePath.lastIndexOf(".") + 1);
+console.log(`The extenction of the file is ${ext}`);
 
-const dir = ;
-const ext = ;
-
-// https://www.google.com/search?q=slice+mdn
+// https://www.google.com/search?q=slice+mdn

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

@@ -3,7 +3,9 @@ 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?
-// Try breaking down the expression and using documentation to explain what it means
+// In this exercise, you will need to work out what num represents?It gives us a random number between 1-100
+// Try breaking down the expression and using documentation to explain what it means? + minimum shifts it between 1-100 so the minimum number is 1 and the biggest one is 100
+//Math.random gives us a random number between 0-1 and the next parantecec returns 100
+//after that we multiple these two given values between 0-100 and the floor methode rounds down the given value and then adding 1(minimum) to the result.
 // 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

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

@@ -1,2 +1,2 @@
-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? we can put back slash to change it into comments.

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;
+// the vatriable age was declared as a const variable and trying to assigne another value caused a TypeError: Assignment to constant variable.
+let age = 33;
 age = age + 1;
+console.log(age);

Sprint-2/2-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 ?
+// what's the error?in the original code,line 4 creates it and line 3 uses the createOfBirth,Then I changed console.log to the next line because we need to declare the variable before using it.
+//ReferenceError: Cannot access 'cityOfBirth' before initialization
 
-console.log(`I was born in ${cityOfBirth}`);
 const cityOfBirth = "Bolton";
+console.log(`I was born in ${cityOfBirth}`);

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

@@ -1,9 +1,11 @@
 const cardNumber = 4533787178994213;
-const last4Digits = cardNumber.slice(-4);
-
+const last4Digits = String(cardNumber).slice(-4);
+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
+// Before running the code, make and explain a prediction about why the code won't work?this function works on string NOT numbers
 // 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
+
+// The .slice() method works on strings, but numbers don't have a .slice() method and it will cause this error : cardNumber.slice is not a function and I think it's kind of type error.

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

@@ -1,2 +1,3 @@
-const 12HourClockTime = "8:53pm";
-const 24hourClockTime = "20:53";
+const twelveHourClockTime = "8:53pm";
+const twentyFourHourClockTime = "20:53";
+// a variable name cannot start with a number and it will cause a SyntaxError

Sprint-2/3-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;
@@ -11,12 +11,29 @@ 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
+// 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:
+//replaceAll
+//Line 4 and 5
+//Number(...)
+//Line 4 and 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?
+//error:line 5,SyntaxError: missing ) after argument list,there is a missing comma between the two arguments "," and " "
 
 // 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
+//let priceAfterOneYear
+//const priceDifference
+//const percentageChange
 
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+//it removes all commas from the string
+//converts the string "10000" into the number 10000
+//The purpose is to turn the price from a formatted string into a number

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

@@ -11,15 +11,26 @@ 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?
+// a) How many variable declarations are there in this program? six variable,1-movieLenghth , 2- remainingSeconds
+//3-totalMinutes  , 4- totalHours , 5- result .
 
-// b) How many function calls are there?
+// b) How many function calls are there? one function ,line 10 : console.log()
 
-// c) Using documentation, explain what the expression movieLength % 60 represents
+// c) Using documentation, explain what the expression movieLength % 60 represents?
+//8784 % 60=24
+//The % operator is called the remainder operator.
+//It gives you the remainder left over after division.
+//we can calculate the number of the left seconds after converting the movie length into whole minutes, 24 seconds left over after converting the movie's total length into whole minutes.
 // 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?
+// d) Interpret line 4, what does the expression assigned to totalMinutes mean?This removes the seconds that don't make up a complete minute.
+//Then it divides that number by 60 to convert the seconds into whole minutes.
+//we have 8784 seconds so
 
-// e) What do you think the variable result represents? Can you think of a better name for this variable?
+//8784 - 24 = 8760
+//8760 / 60 = 146 it is the total minutes
 
+// e) What do you think the variable result represents? Can you think of a better name for this variable?creates a formatted representation of the movie's length in hours, minutes, and seconds.
+//I can name it the movie duration
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+//Works properly for non-negative whole-number seconds; decimals/negative values cause formatting problems

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

@@ -2,13 +2,13 @@ const penceString = "399p";
 
 const penceStringWithoutTrailingP = penceString.substring(
   0,
-  penceString.length - 1
+  penceString.length - 1,
 );
 
 const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");
 const pounds = paddedPenceNumberString.substring(
   0,
-  paddedPenceNumberString.length - 2
+  paddedPenceNumberString.length - 2,
 );
 
 const pence = paddedPenceNumberString
@@ -22,6 +22,18 @@ console.log(`£${pounds}.${pence}`);
 
 // You need to do a step-by-step breakdown of each line in this program
 // Try and describe the purpose / rationale behind each step
+//this function penceString.length-1 removes the last p from string so it values 3 because it contains 4 characters minues 1.
+//penceString.substring(0, 3) and it takes the characters from position 0 up to, but not including, position 3.
+//const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");This uses padStart() to make sure the string has at least 3 characters.
+//padStart() adds characters to the begining of a string to make it 3 character long.
 
-// To begin, we can start with
-// 1. const penceString = "399p": initialises a string variable with the value "399p"
+//const pounds = paddedPenceNumberString.substring(0, paddedPenceNumberString.length - 2);
+// we remove the last two characters and stores the remaining part of the string as pounds.
+//This line extracts the pounds part.
+//line14:penceString = "399p"
+
+//paddedPenceNumberString is "399".
+//The substring() takes the last two characters as pence., so:"399" → "99"
+//Then .padEnd(2, "0") checks the string is at least 2 characters long. If it already has 2 characters, like "99", without changing the rest.
+//padEnd(2, "0") adds "0" to the end of the string until it reaches a length of 2.
+//finally line 18 combines pound and pence which is £3.99

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

@@ -8,8 +8,9 @@ Let's try an example.
 In the Chrome console, invoke the function `alert` with one argument, the string `"Hello world!"`;
 
 What effect does calling the `alert` function have?
+alert() is a function that displays a message to the user.its return value is undefined.
 
 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?It provides a text box where the user can enter their name, along with buttons such as OK and Cancel.
+What is the return value of `prompt`? prompt() returns a value.