Sheffield | May-2025 | Mayowa Fadare | Structuring and Testing Data Sprint-1

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

@@ -4,3 +4,4 @@ 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 increases the variable by adding +1 to the initial 

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

@@ -1,11 +1,16 @@
-let firstName = "Creola";
+let firstName  = "Creola";
 let middleName = "Katherine";
-let lastName = "Johnson";
+let lastName   = "Johnson";
 
+// Grab the first character of each name dynamically
+const initials = firstName[0] + middleName[0] + lastName[0];
+
+console.log(initials); // CKJ
 // 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 = ``;
+
+
 
 // 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 = base.slice(lastDotIndex);
+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 +7,8 @@ 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
+// Math.random() returns a random number in the interval (0,1 )
+// Math.random() * (maximum - minimum + 1)  this means the random decimal number will be multiplied by the range difference between maximum and minimum plus 1
+// For minimum = 1 and maximum = 100, the range size is 100 - 1 + 1 = 100,
+// Math.floor() rounds down to the nearest whole number
+// + minimum shifts the entire range up, by the minimum value 1 and not 0

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

@@ -1,2 +1,4 @@
-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?
+// To prevent computer running two lines consecutively, we use double slash (//) at the beginning of each line.
+

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

@@ -1,4 +1,6 @@
 // trying to create an age variable and then reassign the value by 1
 
 const age = 33;
-age = age + 1;
+// age = age + 1;
+// let age = 33;
+// const.log(age);

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

@@ -2,4 +2,7 @@
 // what's the error ?
 
 console.log(`I was born in ${cityOfBirth}`);
+// const cityOfBirth = "Bolton";
+
 const cityOfBirth = "Bolton";
+console.log(`I was born in ${cityOfBirth}`); 

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

@@ -7,3 +7,9 @@ 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
+// const last4Digits = cardNumber.toString().slice(-4);
+console.log(last4Digits);
+//.slice() is a method for strings and arrays, not numbers, and a cardNumber consist of number.
+// after running the code, it gave TypeError: cardNumber.slice is not a function
+// This was not what i predicted, and it gave the error due to javascript not recognising the command cardNumber.slice(-4);
+// had to use the recognised command cardNumber.toString().slice(-4); for it to be recognised.

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

@@ -1,2 +1,10 @@
 const 12HourClockTime = "20:53";
-const 24hourClockTime = "08:53";
+const 24hourClockTime = "08:53";
+
+
+const hour12ClockTime = "20:53 PM";
+const hour24ClockTime = "08:53";
+console.log(hour12ClockTime);
+console.log(hour24ClockTime);
+it gave a SyntaxError: Identifier directly after number, which mean a variable starting with a number, which is not allowed in js.
+

Sprint-1/3-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;
@@ -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
-
+// There are 5 function calls on this file: in line 1, 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?
-
+// The error comes from line 5, SyntaxError: Unexpected token, expected "," (5:60), can be corrected by adding coma (",","")
 // c) Identify all the lines that are variable reassignment statements
-
+// Line number 4 and 5
 // d) Identify all the lines that are variable declarations
-
+// Line number 1,2,7 and 8 
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+// To remove the commas in the string price and convert it to a numerical value (e.g., "10,000" to 10000)..

Sprint-1/3-mandatory-interpret/2-time-format.js

@@ -12,14 +12,15 @@ 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 variables
 // b) How many function calls are there?
-
+// There is 1 function
 // 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 calculates the remainder when movieLength (in seconds) is divided by 60.
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
-
+// line 4 means total and exact amount of movie length after removing the remaining seconds not used for movie
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
-
+// it represent the total time used for the movie in Hours, minutes and seconds. a better name could be movieduration
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+// yes it will work, provided there are no negative integer

Sprint-1/3-mandatory-interpret/3-to-pounds.js

@@ -13,7 +13,7 @@ const pounds = paddedPenceNumberString.substring(
 
 const pence = paddedPenceNumberString
   .substring(paddedPenceNumberString.length - 2)
-  .padEnd(2, "0");
+
 
 console.log(`£${pounds}.${pence}`);
 
@@ -25,3 +25,12 @@ console.log(`£${pounds}.${pence}`);
 
 // To begin, we can start with
 // 1. const penceString = "399p": initialises a string variable with the value "399p"
+
+// const penceStringWithoutTrailingP = penceString.substring(0, penceString.length - 1); removes the trailing p from the penceString, so the value will be "399".
+
+// const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0"); pads the numeric string with zeros until it 3 digits character Long. value will be "399" and also ensuring consistency of 3 digits value.
+
+// const pounds = paddedPenceNumberString.substring(0, paddedPenceNumberString.length - 2); extracts the pounds part from the padded string by taking all but the last two digits.Here, it will be "3".
+
+// const pence = paddedPenceNumberString.substring(paddedPenceNumberString.length - 2).padEnd(2, "0");  extracts the last two characters as the pence portion and ensures it is always two digits.
+// console.log(`£${pounds}.${pence}`); formats and prints the final price in pounds and pence format, hence it will output "£3.99"