Completed the key exerices

Author: MehrozMunir

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

@@ -4,3 +4,6 @@ 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 is adding 1 to count variable and then saving this new value to count variable
+// = sign is being used to assign the new value of count to the count variable

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

@@ -6,6 +6,6 @@ let lastName = "Johnson";
 // 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 = ``;
+initials = firstName.charAt(0) + middleName.charAt(0) + lastName.charAt(0);
 
 // https://www.google.com/search?q=get+first+character+of+string+mdn
-

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

@@ -12,12 +12,14 @@
 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}`);
+console.log(`The base part of ${filePath} is: \n ${base}` + "\n");
 
 // 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);
+console.log(`The dir part of ${filePath} is: \n ${dir}` + "\n");
+const ext = filePath.slice(filePath.lastIndexOf("."));
+console.log(`The ext part of ${filePath} is: \n ${ext}`);
 
-// https://www.google.com/search?q=slice+mdn
+// https://www.google.com/search?q=slice+mdn

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

@@ -2,8 +2,20 @@ 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 in the above code represents integer numbers from 1 to 100
+// Math.random() method used in the above code returns floating numbers between 0(inclusive) and 1(exclusive)
+/*and (maximum - minimum + 1) will give use the number that when multiplied by values between 
+0(inclusive) and 1(exclusive) we will get results from 0 to 99.99999999..... including any decimal values in between
+and the Math.floor is used to get rid of the decimal values and return only numbers; so our
+values will become 0 to 99 only numbers
+and at the end part of the equation we are adding minimum value i.e. 1 which will result in
+assigning values from 1 to 100 in num; that's why we are getting only values from 1 to 100 in our num
+and every time we print the num in console.log() we can get any values between 1 to 100 depending on the radom value returned 
+by the Math.random() method.*/

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

@@ -2,7 +2,9 @@ let carPrice = "10,000";
 let priceAfterOneYear = "8,543";
 
 carPrice = Number(carPrice.replaceAll(",", ""));
-priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ""));
+//priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," "")); //error line of code
+priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," , "")); //fixed
+
 
 const priceDifference = carPrice - priceAfterOneYear;
 const percentageChange = (priceDifference / carPrice) * 100;
@@ -12,11 +14,33 @@ 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
+/* There are three function calls in this file as shown by the following lines from the code:
+carPrice = Number(carPrice.replaceAll(",", ""));
+priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", ""));
+console.log(`The percentage change is ${percentageChange}`);
+
+replaceAll and log are the functions in the above lines */
 
 // 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?
+/* The error is coming from the following line inside the replaceAll method that accepts two parameters separated by comma
+but in our code there is no comma for the separation and that is the problem
+priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ""));
+we can fix this by simply adding the comma after first parameter value as follows:
+priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," , "")); */
 
 // c) Identify all the lines that are variable reassignment statements
+/* The following two lines are the variable reassignment statements:
+carPrice = Number(carPrice.replaceAll(",", ""));
+//priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," "")); */
 
 // d) Identify all the lines that are variable declarations
+/* All the lines that are variable declarations are as follows:
+carPrice = Number(carPrice.replaceAll(",", ""));
+priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," "")); //error line of code
+const priceDifference = carPrice - priceAfterOneYear;
+const percentageChange = (priceDifference / carPrice) * 100; */
 
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+/* This code is replacing all the comma characters with an empty character inside the carPrice String and then converting that String  to a Number
+The purpose of doing this is because in the later part of code we are doing some Math calculations on this number 
+and, therefore, we can't use String, we need to remove the commas in the String and convert that String into a number