London | 26-ITP-Sept | Maharit Belai | Sprint 2 | Course work

Sprint-2/1-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
+// line 3 = it is reassigning a value to the variable count

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

@@ -2,9 +2,5 @@ const firstName = "Creola";
 const middleName = "Katherine";
 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 = ``;
-
-// https://www.google.com/search?q=get+first+character+of+string+mdn
+const initials = `${firstName[0]}${middleName[0]}${lastName[0]}`;
+console.log(initials);

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

@@ -1,23 +1,11 @@
-// The diagram below shows the different names for parts of a file path on a Unix operating system
-
-// ┌─────────────────────┬────────────┐
-// │          dir        │    base    │
-// ├──────┬              ├──────┬─────┤
-// │ root │              │ name │ ext │
-// "  /    home/user/dir / file  .txt "
-// └──────┴──────────────┴──────┴─────┘
-
-// (All spaces in the "" line should be ignored. They are purely for formatting.)
-
 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 startDirIndex = filePath.lastIndexOf("/Users");
+const dir = filePath.slice(startDirIndex, lastSlashIndex);
+console.log(`The dir part of ${filePath} is ${dir}`);
+const dotIndex = filePath.lastIndexOf(".");
+const ext = filePath.slice(dotIndex);
+console.log(`The ext part of the ${filePath} is ${ext}`);

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

@@ -3,7 +3,11 @@ 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
-// 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
+//1.num represents a number which is an Integer.
+//2.lets start by (maximum-minimum +1) which the output is 100.
+//3.math.random()*100 returns random number between 0 and 100, what actually
+//  happens is that math.randum gives out random number from 0 to 1 which 1 is
+//  not included and in this case, multiply the output by 100.
+//4.math.floor()it rounds a number to thier nearest integer, which means it drops all the decimal.
+//5.at the end we add 1 which is the minimum.
+console.log(num);

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?

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

@@ -1,4 +1,6 @@
 // trying to create an age variable and then reassign the value by 1
 
-const age = 33;
+let age = 33;
 age = age + 1;
+// you can not reassign a value to variable that is declared const.
+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 ?
 
-console.log(`I was born in ${cityOfBirth}`);
 const cityOfBirth = "Bolton";
+// The error is that the const declation and initialization came after console.log so no access for cityOfBirth.
+console.log(`I was born in ${cityOfBirth}`);

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

@@ -1,9 +1,6 @@
-const cardNumber = 4533787178994213;
+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
+// the code is not working because the number initialized should be in "" .
+// so it can know it/or treat it as a string.
+console.log(last4Digits);

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

@@ -1,2 +1,6 @@
-const 12HourClockTime = "8:53pm";
-const 24hourClockTime = "20:53";
+const HourClockTime = "8:53pm";
+const hourClockTime = "20:53pm";
+
+// The error here is that the variable started with number.
+console.log(HourClockTime);
+console.log(hourClockTime);

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

@@ -2,21 +2,21 @@ 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
-
-// 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?
-
-// c) Identify all the lines that are variable reassignment statements
-
-// d) Identify all the lines that are variable declarations
-
-// e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+//1. There are 5 function calls in line 4 , 5 and 10
+//     * number()and the second one is .replaceall() in line 4
+//      * number() and the second one is .replaceall()in line 4
+//      * console.log()
+// 2. The error is coming from the line 5, because there was no comma in the replaceAll() method .
+// 3. line 4 and 5 are the variable reassignment statments.
+// 4. line 1 ,2 ,7 and 8 are lines where variable declarions happened
+// 5. *The method .replaceAll() in line 4 is replacing the coma (,) with nothing("") in the "10,000" and the output is "10000",
+//     the number() function converts the string "10000" into a number.
+//    *The method .replaceAll() in line 4 is replacing the coma(,) with nothing("") in the "8,543" and the output is "8543"
+//        the number() function coverts the string "8543" into a number which is 8543.

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

@@ -9,17 +9,17 @@ const totalHours = (totalMinutes - remainingMinutes) / 60;
 const result = `${totalHours}:${remainingMinutes}:${remainingSeconds}`;
 console.log(result);
 
-// For the piece of code above, read the code and then answer the following questions
+//A.There are six variable declarations
 
-// a) How many variable declarations are there in this program?
+//B. one function call (console.log())
 
-// b) How many function calls are there?
+//C.The % represents a remainder. The operator returns the remainder leftover when one operand  which in
+//  this cas is movieLength is divided by a second operand in this case 60%.
 
-// c) Using documentation, explain what the expression movieLength % 60 represents
-// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators
+// D.it means it is changing the value that was in second into minute by dividing it 60 after the top
+// calculation makes it whole number.
 
-// d) Interpret line 4, what does the expression assigned to totalMinutes mean?
+//E. It represents the duration of the movie.movieLength/movieDuration.
 
-// e) What do you think the variable result represents? Can you think of a better name for this variable?
-
-// f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+//F. No it doesnt work for all different values , I experimented it with -ve numbers and decimals.It doesnt
+//   give the desired output

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 +25,15 @@ console.log(`£${pounds}.${pence}`);
 
 // To begin, we can start with
 // 1. const penceString = "399p": initialises a string variable with the value "399p"
+
+// 2. penceStringWithoutTrailingP : it's value is the return of the method substring()which is 399.
+// the substring(0,3-1),when the substring extracts string  from index 0 to 2 =>399 and p will be dropped.
+
+// 3. paddedPenceNumberString  : its value is what the padstart() method returns which is the same.399
+//padstart(3,0),it is supossed to add  0's till the needed length is reached which is 3=>399.
+
+// 4. const Pound is initialized by the out come of the substring()method which is only 3. Because the
+// substring start index is zero and end endex is 1.
+// 5. const pence will be initialized there are two methods. the first one will extract the string form index 1
+// the second one will add  0 which there is no need=> 99
+//6.consol.log => 3.99