completed sprint 1 exercises

Author: Samual-Hu

Sprint-1/1-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
+
+// Line 3 is reassigning a new value to the 'count' variable.
+// In JavaScript, '=' is the assignment operator, not a mathematical equals sign. 
+// It first evaluates the expression on the right side (count + 1, which is 0 + 1), 
+// and then assigns that result (1) back to the variable on the left side, updating its value.

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

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

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

@@ -17,7 +17,8 @@ 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("."));
+console.log(`The dir part of ${filePath} is ${dir}`);
+console.log(`The ext part of ${filePath} is ${ext}`);
 // https://www.google.com/search?q=slice+mdn

Sprint-1/1-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);
+// Answer: The variable `num` represents a random whole number between 1 and 100 (inclusive).
+// Breakdown of the expression:
+// 1. Math.random() generates a random decimal number between 0 (inclusive) and 1 (exclusive).
+// 2. (maximum - minimum + 1) calculates the total number of possible integers in our range (which is 100).
+// 3. Multiplying them scales the random decimal to be between 0 and 99.999...
+// 4. Math.floor() rounds that decimal down to the nearest whole number (getting an integer from 0 to 99).
+// 5. Finally, '+ minimum' shifts the starting point up by 1, resulting in a final integer from 1 to 100.

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

@@ -1,4 +1,4 @@
 // trying to create an age variable and then reassign the value by 1
 
-const age = 33;
+let age = 33;
 age = age + 1;

Sprint-1/2-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}`);
+

Sprint-1/2-mandatory-errors/3.js

@@ -1,6 +1,6 @@
-const cardNumber = 4533787178994213;
+const cardNumber = "4533787178994213";
 const last4Digits = cardNumber.slice(-4);
-
+console.log(last4Digits);
 // 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

Sprint-1/2-mandatory-errors/4.js

@@ -1,2 +1,5 @@
-const 12HourClockTime = "20:53";
-const 24hourClockTime = "08:53";
+const time12Hour = "20:53";
+const time24Hour = "08:53";
+
+console.log(time12Hour);
+console.log(time24Hour);

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

@@ -12,11 +12,12 @@ 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
-
+// Answer: There are 5 function calls in total. They are located on lines 4, 5, and 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?
-
+// Answer: The error comes from line 5. It occurs because we are trying to reassign a value to `priceAfterOneYear`, which was originally declared as a `const`. To fix it, change `const` to `let` on line 2.
 // c) Identify all the lines that are variable reassignment statements
-
+// Answer: Lines 4 and 5.
 // d) Identify all the lines that are variable declarations
-
+// Answer: Lines 1, 2, 7, and 8.
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+// Answer: It removes the comma from the string using `replaceAll()`, and then converts that cleaned string into a number type using `Number()`. The purpose is to convert a formatted text string into a valid mathematical number so we can do calculations with it later.