Manchester | 26-ITP-Sep | Fatima Rouchi | Sprint 2 | Complete 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
+console.log(`${count}`);
+
+// line 3 is reassigning the value of count by changing it to count+1
+// and the = sign takes the value on the right and stores it into the variable on the left
+// in this case in line 3 the the variable is assigned a new value telling it to take the old one and add 1 to it.

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

@@ -5,6 +5,7 @@ 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[0] + middleName[0] + lastName[0];
+console.log(`${initials}`);
 
 // https://www.google.com/search?q=get+first+character+of+string+mdn

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

@@ -17,7 +17,10 @@ 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);
+const ext = filePath.slice(filePath.lastIndexOf("."));
 
-// https://www.google.com/search?q=slice+mdn
+console.log(`The directory of ${filePath} is ${dir}`);
+console.log(`The extension of ${filePath} is ${ext}`);
+
+// https://www.google.com/search?q=slice+mdn

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

@@ -7,3 +7,11 @@ 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);
+// num is a random whole number between minimum and maximum.
+// Math.random() returns a number that's greater than or equal to 0 and less than 1.
+/*Then we multiply by (maximum - minimum + 1) to get a range of possible values, which means 
+  all the values num could end up being. In this program, num can be any whole number from 1 to 100, inclusive
+  so both 1 and 100 are possible.*/
+// Math.floor(...) turns that into a whole number.
+// Finally, we add minimum so the number starts at minimum instead of 0.

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

@@ -1,2 +1,3 @@
-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 +1,7 @@
 // trying to create an age variable and then reassign the value by 1
 
-const age = 33;
+/*const makes the variable fixed, so age cannot be changed. to reassign the value
+I need to change const to let.
+*/
+let age = 33;
 age = age + 1;

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

@@ -1,5 +1,8 @@
 // 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}`);
+/* The log was trying to use cityOfBirth before the variable exists.
+ JavaScript reads the code in order, so the variable must be declared before it is used.*/
+// I logged the message before creating the cityOfBirth variable, so JavaScript couldn't find it yet. I need to declare the variable before using it.
 const cityOfBirth = "Bolton";
+console.log(`I was born in ${cityOfBirth}`);

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

@@ -1,9 +1,18 @@
-const cardNumber = 4533787178994213;
-const last4Digits = cardNumber.slice(-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
+
+//This won’t work because cardNumber is a number, and numbers don’t have the slice method.
+//console.log(`${last4Digits}`);
+// when I run it I see: TypeError: cardNumber.slice is not a function because slice() only works on strings or arrays.
+// To fix it, I need to turn the number into a string first, then slice the last 4 characters.
+const cardNumber = 453787178094213;
+const last4Digits = String(cardNumber).slice(-4);
+
+console.log(last4Digits);

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

@@ -1,2 +1,6 @@
-const 12HourClockTime = "8:53pm";
-const 24hourClockTime = "20:53";
+/*const 12HourClockTime = "8:53pm";
+const 24hourClockTime = "20:53";*/
+//JavaScript does not allow variable names that start with digits.
+
+const twelveHourClockTime = "8:53pm";
+const twentyFourHourClockTime = "20:53";

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;
@@ -20,3 +20,29 @@ console.log(`The percentage change is ${percentageChange}`);
 // 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?
+
+// Answers:
+/*a) in total there are 5 function calls in the file:
+carPrice.replaceAll(",", "")
+Number(carPrice.replaceAll(",", ""))
+priceAfterOneYear.replaceAll(",", "")
+Number(priceAfterOneYear.replaceAll(",", ""))
+console.log(...) */
+
+/* b) The problem is on line 5. replaceAll is missing the comma between its
+   two inputs, so JavaScript can’t read it properly. Once I add the comma,
+   the function works normally. correct version (priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", ""));*/
+
+/* c) The reassignment statements are:
+-carPrice = Number(carPrice.replaceAll(",", ""));
+-priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," "")); */
+
+/* d) The variable declaration are:
+-let carPrice = "10,000";
+-let priceAfterOneYear = "8,543";
+-const priceDifference = carPrice - priceAfterOneYear;
+-const percentageChange = (priceDifference / carPrice) * 100; */
+
+/* e) the expression Number(carPrice.replaceAll(",",""))  removes the commas from the price string
+ and then converts it into a number. This is done so the price can be used in 
+ calculations like subtraction and division. */

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

@@ -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 declarations in total: movieLength, remainingSeconds, totalMinutes, 
+    remainingMinutes, totalHours, and result.*/
 
 // b) How many function calls are there?
+// -There is one function call:  console.log(result);
 
 // c) Using documentation, explain what the expression movieLength % 60 represents
 // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators
+/* -The expression movieLength %60 means find the reminder after dividing by 60.
+    It represents the number of seconds left over after all the full minutes have been removed. */
 
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
+/* -The expression assigned to totalMinutes removes the leftover seconds and then divides
+    the remaining total seconds by 60. This gives the total number of whole minutes.*/
 
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
+/* -The variable result represents the movie length as a readable time string in the format hours:minutes:seconds. 
+    A better name could be formattedTime or timeString.*/
 
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+/* -This code works for normal values of movieLength that are non-negative whole numbers of seconds. 
+    it does not work for negative values and 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 +25,15 @@ console.log(`£${pounds}.${pence}`);
 
 // To begin, we can start with
 // 1. const penceString = "399p": initialises a string variable with the value "399p"
+
+// Step-by-step breakdown:
+//const penceString = "399p"; creates a string containing the amount in pence, including the letter p.
+/*const penceStringWithoutTrailingP = penceString.substring(0, penceString.length - 1); 
+ removes the final p so the string becomes "399".*/
+/*const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0"); 
+makes sure the number has at least 3 characters by adding leading zeros if needed.*/
+/*const pounds = paddedPenceNumberString.substring(0, paddedPenceNumberString.length - 2);
+ takes the part before the last 2 digits, which is the pounds value.*/
+/*const pence = paddedPenceNumberString.substring(paddedPenceNumberString.length - 2).padEnd(2, "0"); 
+takes the last 2 digits, which are the pence value, and makes sure they are 2 digits long.*/
+/*console.log(`£${pounds}.${pence}`); prints the final money value in pounds format, like£3.99`.*/