Completed Sprint 1 coursework

Author: Shayida999

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

@@ -4,4 +4,7 @@ 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 taking the current value to count, then make the count to new value
+
+Answer:
+
+//Line 3 is assignment statement,its taking the current value to count,then make the count to a new value.

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

@@ -5,7 +5,8 @@ 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 = ``;
+Answer:
+let 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

@@ -16,8 +16,10 @@ 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 = ;
+Anwer:
+const dir = filePath.slice(0, lastSlashIndex);
+const ext = base.slice(lastDotIndex + 1);
+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 +7,16 @@ 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
+
+Answer:
+
+//num is a random number between 1 and 100.
+
+//Math.random() makes a number between 0 and 1.
+
+//times (maximum - minimum + 1) makes it bigger.
+
+//Math.floor cuts off the decimal.
+
+//+ minimum makes sure the random number starts at 1 instead of 0
+

Sprint-1/2-mandatory-errors/0.js

@@ -1,2 +1,6 @@
 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?
+We don't want the computer to run these 2 lines - how can we solve this problem?
+
+Answer:
+//We can turn those lines into comments by putting // at the start.
+//Then computer ignores them but humans can still read/see them.

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

@@ -2,3 +2,10 @@
 
 const age = 33;
 age = age + 1;
+
+Answer:
+
+//This gives an error because we used const, which can't be changed.
+// If we want to update the value, we should use let instead of const.
+let age = 33;
+age = age + 1;

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

@@ -3,3 +3,12 @@
 
 console.log(`I was born in ${cityOfBirth}`);
 const cityOfBirth = "Bolton";
+
+
+Answer:
+
+//Error because cityOfBirth is used before it is declared.
+//We need to define the variable first, then use it.
+
+const cityOfBirth = "Bolton";
+console.log(`I was born in ${cityOfBirth}`);

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

@@ -7,3 +7,12 @@ const last4Digits = cardNumber.slice(-4);
 // 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
+
+Answer:
+
+//I guessed it breaks because slice is for strings but cardNumber is a number.
+//When I try it, the error says slice is not a function (so I was right).
+//Fix: change the number to string first, then slice works.
+const cardNumber = 4533787178994213;
+const last4Digits = cardNumber.toString().slice(-4);
+console.log(last4Digits); // 4213

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

@@ -1,2 +1,10 @@
 const 12HourClockTime = "20:53";
-const 24hourClockTime = "08:53";
+const 24hourClockTime = "08:53";
+
+
+Answer:
+
+// The first line is wrong cuz variable names can't start with a number.
+// We should rename it like hour12ClockTime or something that doesn't start with a digit.
+const hour12ClockTime = "20:53";
+const hour24ClockTime = "08:53";

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

@@ -12,11 +12,26 @@ 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
+carPrice = Number(carPrice.replaceAll(",", ""));
+priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ""));
+console.log(`The percentage change is ${percentageChange}`);
+
 
 // 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?
+priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ""));
+fix;
+priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", ""));
 
 // c) Identify all the lines that are variable reassignment statements
+carPrice = Number(carPrice.replaceAll(",", ""));
+priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ""));
 
 // d) Identify all the lines that are variable declarations
+let carPrice = "10,000";
+let priceAfterOneYear = "8,543";
+
 
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+replaceAll gets rid of the commas → "10,000" becomes "10000".
+Number() turns that string into the number 10000.
+so we can do maths with it.