London | 26-ITP-Sep | Shirin Panahian | Sprint 2 | Complete Sprint 2 Coursework

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

@@ -3,4 +3,5 @@ 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
+// Line 3 add 1 to value of count and store result back in count,
+// in this line = is not mean (is equal to ), It is a assignment

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

@@ -1,10 +1,6 @@
 const firstName = "Creola";
 const middleName = "Katherine";
 const lastName = "Johnson";
+const initials = `${firstName.charAt(0)}` + `${middleName.charAt(0)}` + `${lastName.charAt(0)}`;
+console.log(`${initials}`);
 
-// 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 = ``;
-
-// https://www.google.com/search?q=get+first+character+of+string+mdn

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

@@ -13,11 +13,7 @@ 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 ${base}`);
-
-// Create a variable to store the dir part of the filePath variable
-// Create a variable to store the ext part of the variable
-
-const dir = ;
-const ext = ;
-
-// https://www.google.com/search?q=slice+mdn
+const dir = filePath.slice(0, `${lastSlashIndex}`);
+const ext = filePath.slice(filePath.lastIndexOf("."));
+console.log(`The dir part of ${filePath} is ${dir}`);
+console.log(`The ext part of this URL is ${ext}`);

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

@@ -1,9 +1,12 @@
 const minimum = 1;
 const maximum = 100;
-
 const num = Math.floor(Math.random() * (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
+//num represents a random whole number between 1 and 100,
+//first we calculate value inside parentheses(maximum - minimum +1) = 100 -1 + 1 =100
+// math.random return number between 0 and 1
+// math.random() * 100 give us a decimal number
+// math.floor round down the number
+// add 1 to the result
+//for example math.floor((0.783 *100))=78 + 1 = 79

Sprint-2/2-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?
+
+/*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 "//" in the beginning of the line so computer ignore them
+// or put them between /* and */

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

@@ -1,4 +1,7 @@
 // trying to create an age variable and then reassign the value by 1
 
-const age = 33;
+let age = 33;
 age = age + 1;
+console.log(`${age}`);
+//We should use let if we want to change the value.
+//Before I changed const to let node show this error message: (Assignment to constant variable.)

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

@@ -1,5 +1,5 @@
 // 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}`);
+// This error (Cannot access 'cityOfBirth' before initialization) is because we need to declare the variable before using it.

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

@@ -1,9 +1,4 @@
 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
+const last4Digits = String(cardNumber).slice(-4);
+console.log(`${last4Digits}`);
+// we get error (cardNumber.slice is not a function) because slice is a String method

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

@@ -1,2 +1,3 @@
-const 12HourClockTime = "8:53pm";
-const 24hourClockTime = "20:53";
+const HourClockTime12 = "8:53pm";
+const hourClockTime24 = "20:53";
+//JavaScript variable names cannot start with a number.

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;
@@ -12,11 +12,23 @@ 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 and Line 5
+    replaceAll() - Line 4 and Line 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 , There is a comma missing between "," and ""*/
 
 // c) Identify all the lines that are variable reassignment statements
+/* Line 4 :carPrice = Number(carPrice.replaceAll(",", ""));
+       Line5 : priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", ""));
+       carPrice and priceAfterOneYear were already declared on Line 1 and 2 using let */
 
 // d) Identify all the lines that are variable declarations
+/* Line 1 : let carPrice = "10,000";
+          Line 2 : let priceAfterOneYear = "8,543";
+          Line 7 : const priceDifference = carPrice - priceAfterOneYear;
+          Line 8 : const percentageChange = (priceDifference / carPrice) * 100;*/
 
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+/*replaceAll remove all the commas from the string and Number convert string  to the number*/

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

@@ -1,4 +1,4 @@
-const movieLength = 8784; // length of movie in seconds
+const movieLength = -98; // length of movie in seconds
 
 const remainingSeconds = movieLength % 60;
 const totalMinutes = (movieLength - remainingSeconds) / 60;
@@ -12,14 +12,25 @@ 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?
+/* there are 6 variable declaration in this program.
+            1- movieLength , 2- remainingSeconds , 3- totalMinutes
+            4- remainingMinutes , 5- totalHours , 6- result */
 
 // b) How many function calls are there?
+/* one function 
+            Line 10 : console.log(); */
 
 // c) Using documentation, explain what the expression movieLength % 60 represents
 // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators
+// Remainder(%) : Return the remainder left over when one operand is divided by a second operand
+// console.log(13 % 5 ); 3
 
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
+// This expression converts movie length from seconds into minutes
 
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
+// Variable result represent the movie length formatted as hours, minutes, seconds ,
+// another name could be movieTime
 
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+//So the code works properly for whole numbers, but not for negative numbers and decimal numbers because the result can contain decimal values.

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
@@ -25,3 +25,19 @@ 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);
+//     create a new variable and put the string without p
+
+// 3.  const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");
+//     padStart() adds characters to the beginning of a string to make it 3 characters long.
+//     because we need to convert it to pound and pence
+
+// 4. const pounds = paddedPenceNumberString.substring(0,paddedPenceNumberString.length - 2);
+//    We remove the last 2 characters and store the remaining part of the string as pounds.
+
+// 5. const pence = paddedPenceNumberString.substring(paddedPenceNumberString.length - 2).padEnd(2, "0");
+//     Gets the last two characters as pence.”
+
+// 6. console.log(`£${pounds}.${pence}`);
+//.   Finally combine pound and pence

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

@@ -8,8 +8,11 @@ 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(): shows the message to the users. in this case show "Hello world!" in the box and we can close it or click on the 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 effect does calling the `prompt` function have? 
+prompt(): returns whatever the user enters. It is provide a textbox that we can type on it.
 What is the return value of `prompt`?
+The Return value of prompt is the text enter by user. in this example return name that we write in the box.

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

@@ -5,12 +5,18 @@ 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?
+console stores object. It stores a collection of methods that allow you to interact with the browser's developer console.
+what does the syntax `console.log` or `console.assert` mean? In particular, what does the `.` mean?
+access the log property/method of the console object.
+access the assert method of the console object.