London | 26-ITP-Sep| Abdennour Hachemi| Sprint 2 | Coursework

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

@@ -4,3 +4,8 @@ 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
+
+/*
+In line 3 the code is incrmenting the variable "count" by 1 , the operator "=" is assigning a new value to "count" by adding 1.
+
+*/

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

@@ -2,9 +2,14 @@ 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 = ``;
+const initials = `${firstName.charAt(0)}${middleName.charAt(0)}${lastName.charAt(0)}`
 
 // https://www.google.com/search?q=get+first+character+of+string+mdn
+
+
+console.log(initials)

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

@@ -17,7 +17,17 @@ 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);
+ /*correction : slice(0,lastSlashIndex); is the correct method to extract the dir path
+    filePath.slice(start, end) => 0 represents the character 0 of the filePath String put 1 will skip the first charchter.
+ */
+
+
+ const ext = filePath.slice(filePath.lastIndexOf(".")+1);
+
+// https://www.google.com/search?q=slice+mdn
+
+console.log(`The dir part of the filePath ${filePath}variable is ${dir}`);
+
+console.log(`The ext part of a variable file.txt is ${ext}`);
 
-// https://www.google.com/search?q=slice+mdn

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

@@ -7,3 +7,21 @@ const num = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum;
 // 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
+
+console.log(num);
+
+//First operation 
+// num is generating  a random dicimal number with method Math.random() between 0 and 1 result eg :0.3948605
+
+
+
+//Second operation
+//The generated number is multiplied by the range+1  which is between 1-100 result eg 39.48605
+
+
+ //Third operation 
+ //num is rounded down to the nearset whole number using the method Math.floor restult eg 39.48605 => 39
+
+
+
+  // Last operation is to add the  "minimum" (in this case it's 1 or it can be changed to any changed number e.g 10) this will shift the random number so it starts counting from minimum, instead of from zero.

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 +1,11 @@
 // trying to create an age variable and then reassign the value by 1
 
-const age = 33;
+let age = 33;
 age = age + 1;
+
+/*
+Answer : The Error is  : TypeError: Assignment to constant variable.
+Constants in JavaScript can't be reassigned to correct this we have to change the varible type from const => let.
+
+*/
+console.log(age)

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

@@ -1,5 +1,10 @@
 // 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}`);
+//Answer : the error was that CitOfBirth vaiable was declared after the method cosole .log()
+ //The solution is to declare it before calling it.
+
 const cityOfBirth = "Bolton";
+
+console.log(`I was born in ${cityOfBirth}`);
+

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

@@ -1,9 +1,21 @@
 const cardNumber = 4533787178994213;
-const last4Digits = cardNumber.slice(-4);
+const last4Digits = cardNumber.toString().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 : The slice method is used with String data type. here we have cardNumber varible with type Number.
+Running the code will give a TypeError : cardNumber.slice is not a function
+The solution is to convert numbe to string, There are three posibility:
+String(cardNumber)
+cardNumber.toString()
+`${cardNumber}`
+
+*/
+
+console.log(last4Digits);

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

@@ -1,2 +1,6 @@
-const 12HourClockTime = "8:53pm";
-const 24hourClockTime = "20:53";
+const HourClockTime12 = "8:53pm";
+const hourClockTime24 = "20:53";
+
+/*
+the naming of of the varibles is not correct varible should not 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;
@@ -13,10 +13,55 @@ console.log(`The percentage change is ${percentageChange}`);
 
 // 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?
 
+/*
+Solution to a)
+
+There are 5 function calls in this file:
+-------------|-----------------| --------|
+        1    |  Number()       | line 4  |
+        2    | replaceAll()    | line 4  |
+        3    |  Number()       | line 5  |
+        4    | replaceAll()    | line 5  |
+        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?
+/*
+Solution to b)
+ After running the code the terminal gives SyntaxError: missing ) after argument list BUT the actual error is not having a comma in line 5 in the replaceAll methode as it needs two arguments
+ eplaceAll("," "") => should be eplaceAll("," , "")
+*/
 // c) Identify all the lines that are variable reassignment statements
+/*
+Solution to c)
+Variable reassignment statements lines are:
+
+line 4 : carPrice = Number(carPrice.replaceAll(",", ""));
+line 5 : priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", ""));
+*/
 
 // d) Identify all the lines that are variable declarations
+/*
+ Solution to d)
+ Variable declarations lines are:
+  line 1 :let carPrice = "10,000";
+  line 2 :let priceAfterOneYear = "8,543";
+  line 7 :const priceDifference = carPrice - priceAfterOneYear;
+c line 8 :const percentageChange = (priceDifference / carPrice) * 100;
+
+*/
 
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+
+/*
+Solution to e)
+The expresssion Number(carPrice.replaceAll(",","")) is removing the comma "," in CarPrice i.e from 10,000 to 10000 which is stored 
+in String type , removing the comma will insure the mathimatical operation will go normal when converted to type Number.
+
+*/
+

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

@@ -1,4 +1,4 @@
-const movieLength = 8784; // length of movie in seconds
+const movieLength = 90.5; // length of movie in seconds
 
 const remainingSeconds = movieLength % 60;
 const totalMinutes = (movieLength - remainingSeconds) / 60;
@@ -11,15 +11,63 @@ 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?
+/************************************************** */
+/* Solution  a): There are 6 varibale declarations */
+/************************************************* */
+
 
 // b) How many function calls are there?
+    /**************************************************/
+     /* Solution  b):                                 */
+     /* There is only one fuction call (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
 
+/*********************************************************************************************************************/
+/*Solution  c):                                                                                                      */
+ /*  The operator (%) called Modulo returns the remainder left over when one operand is divided by a second operand  */
+ /* In this expamle it gives the time remainder of the movie in seconds                                              */
+/*********************************************************************************************************************/
+
+
+
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
 
+ /****************************************************************************************************************************************************************************/
+ /*  Solution  d):                                                                                                                                                           */
+ /*  The totalMinutes expression is calaculated first by subtrackting the lengh of movie by the reminder of seconds which rounds down the nearst minutes                     */
+ /* Since we know the total number of seconds that are multiple of 60 we can can calculate the total  number of minutes by dividing it over 60 since 1 minute is 60 seconds  */
+ /* This way we have the Movie total exact number of miutes.                                                                                                                 */
+ /****************************************************************************************************************************************************************************/
+
+
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
+     /*********************************************************************************************/
+     /* Solution  e):                                                                             */
+     /* The variable result represents the exact lenght of the movie in Hours + Minutes + Seconds */
+     /* A better name for  variable result  could be : extctMovieLength                           */                                                
+     /*********************************************************************************************/
 
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+
+/***************************************************************************************************************************************************************/
+     /* Solution  e):                                                                                                                                          */
+     /*  movieLength = 0    => exactMovieLength = 0:0:0                                                                                                        */                                                                                                      
+     /*  movieLength = 60   => exactMovieLength = 0:1:0                                                                                                        */             
+     /*  movieLength  = 3676 => exactMovieLength = 1:1:16                                                                                                      */
+     /*  movieLength  = -3600 => exactMoveLenght = -1:0:0                                                                                                      */
+     /*  movieLength  = 90000 => exactMoveLenght = 25:0:0                                                                                                      */
+     /*                                                                                                                                                        */
+     /*  This code Could be better:                                                                                                                            */
+     /*  - giving a negative value for  movieLength will result in a negative clock: so there could have message that reject negative numbers.                 */
+     /*  - The program should have represented Hours/Min/Sec in this format 00:00:00 so each time should be represented with 2 digits.                         */
+     /*  - 25 hours exeeds 24 hours which represents a day so a variable total days could be added to represent time in days.                                  */
+     /*  -Values with dicimal numbers will return the clock showing dicimal numbers this should be rounded up or down to the nearst time with an integer number */
+     /*                                                                                                                                                        */
+     /**********************************************************************************************************************************************************/
+

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

@@ -6,10 +6,11 @@ const penceStringWithoutTrailingP = penceString.substring(
 );
 
 const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");
-const pounds = paddedPenceNumberString.substring(
-  0,
+
+const pounds = paddedPenceNumberString.substring( 0,
   paddedPenceNumberString.length - 2
 );
+console.log(pounds)
 
 const pence = paddedPenceNumberString
   .substring(paddedPenceNumberString.length - 2)
@@ -25,3 +26,8 @@ console.log(`£${pounds}.${pence}`);
 
 // To begin, we can start with
 // 1. const penceString = "399p": initialises a string variable with the value "399p"
+// 2. penceStringWithoutTrailingP = penceString.substring(  0,  penceString.length - 1): This line of code slice the penceString varible by removing the "p" character from it.
+// 3. const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0") : This line of code adds "0" if lenght of penceStringWithoutTrailingP is less then 3 i.e e value is "1" => it will convert it to"001" or ifthe value is "22" it will confert it to "022".
+// 4. const pounds = paddedPenceNumberString.substring( 0,  paddedPenceNumberString.length - 2); : This line of code extract and store the value  of pound from paddedPenceNumberString using the substring method since £1 = 100 pences => any number in the hudered position i.e third character from the right onwards has a value of £.
+// 5. const pence = paddedPenceNumberString   .substring(paddedPenceNumberString.length - 2)  .padEnd(2, "0");: This line of code extract and store the value  of pences paddedPenceNumberString using the substring method => instead of starting from the left it start from the right moving two positions then it adds  "0"in case the pences value is less then 10.
+// 6. console.log(`£${pounds}.${pence}`): This line of code prints the final result in $ and pences in nice readable way => £3.99

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

@@ -8,8 +8,13 @@ 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?
+Answer : it will brings a popup with alert message "Hello World"
 
 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`?
+
+Answer: calling the `prompt` function will bring up a dialog box with a field to put an answer
+
+The return value of `prompt is the variable  `myName`