Module-Structuring-and-Testing-Data | Sprint-1

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

@@ -1,6 +1,10 @@
 let count = 0;
 
 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
+
+
+///answer line3 is a statement that increases count by 1. the =operator reassigns the result of count +1 back to the count variable

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

@@ -9,3 +9,7 @@ let initials = ``;
 
 // https://www.google.com/search?q=get+first+character+of+string+mdn
 
+// Get the first character of each name using [0]
+let initials = `${firstName.charAt(0)}${middleName.charAt(0)}${lastName.charAt(0)}`;
+
+console.log(initials);  // Output: CKJ

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

@@ -20,4 +20,11 @@ console.log(`The base part of ${filePath} is ${base}`);
 const dir = ;
 const ext = ;
 
-// https://www.google.com/search?q=slice+mdn
+// https://www.google.com/search?q=slice+mdn
+
+const dir = filePath.slice(0, lastSlashIndex);
+console.log(`The dir part of ${filePath} is ${dir}`);
+
+const lastDotIndex = base.lastIndexOf(".");
+const ext = base.slice(lastDotIndex);
+console.log(`The ext part of ${base} is ${ext}`);

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

@@ -7,3 +7,12 @@ 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
+// 1. Math.random() generates a decimal between 0 (inclusive) and 1 (exclusive)
+// 2. Multiply by (maximum - minimum + 1) to scale to the desired range size
+// 3. Math.floor() rounds down to get an integer from 0 up to range size minus 1
+// 4. Adding minimum shifts the range so the lowest number is minimum, not zero
+const num = 
+Math.floor(Math.random() * (maximum - minimum + 1)) + minimum;
+
+// Result: num is a random integer between minimum and maximum, inclusive
+console.log(num);

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

@@ -1,2 +1,7 @@
 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?
+
+we use // at the beginning of the line
+we wrap it with /**/ if it spans multiple 
+
+Comments are ignored by the JavaScript engine — they're only for humans to read, like notes or documentation.

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

@@ -2,3 +2,14 @@
 
 const age = 33;
 age = age + 1;
+//
+
+// trying to create an age variable and then reassign the value by 1
+
+let age = 33;   //use 'let' instead 'const' that needs to be reassigned
+age = age + 1;
+
+console.log(age);  //log the updated age value
+
+//output:34 
+

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

@@ -1,5 +1,10 @@
-// Currently trying to print the string "I was born in Bolton" but it isn't working...
-// what's the error ?
-
+// Currently trying to print the string "I was born in Bolton' but it is not working...
+// What is the error?
+// 
 console.log(`I was born in ${cityOfBirth}`);
 const cityOfBirth = "Bolton";
+
+// here we first declare cityOfBirth before using it to avoid error
+
+// 
+"

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

@@ -7,3 +7,14 @@ 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
+
+
+//It will throw an error because cardNumber is a number, not a string — and .slice() is a method for strings and arrays, not numbers.
+
+const cardNumber = 4533787178994213;
+//convert number to string before using slice
+const last4Digits = cardNumber.toString().slice(-4);
+//log the last 4 digits
+console.log(last4Digits);
+
+//outcome 4213

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

@@ -1,2 +1,19 @@
 const 12HourClockTime = "20:53";
-const 24hourClockTime = "08:53";
+const 24hourClockTime = "08:53";
+
+
+
+//output the values
+
+
+
+console.log("Clock time in 12h format:", clockTime_12Hour);
+
+
+console.log("Clock time in 24h format:",clockTime_24Hour);
+
+
+
+
+
+

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

@@ -20,3 +20,36 @@ 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) There are 5 function calls in this file. The lines where the function calls are made are:
+// 1. carPrice.replaceAll(",", "") on line 4
+// 2. Number(carPrice.replaceAll(",", "")) on line 4
+// 3. priceAfterOneYear.replaceAll(",", "") on line 5
+// 4. Number(priceAfterOneYear.replaceAll(",", "")) on line 5
+// 5. console.log(`The percentage change is ${percentageChange}`) on line 8 
+
+
+console.log(...)
+
+b)This line has a syntax error: there's an extra quote in replaceAll("," "")
+It should be: replaceAll(",", "")
+
+c) carPrice = Number(carPrice.replaceAll(",", ""));
+priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", ""));
+ These 2 lines are reassignments — the values are being updated after declaration.
+
+ d)This is a nested expression that does two things:
+
+ carPrice.replaceAll(",", ""):
+
+ Replaces all commas with empty strings.
+
+ Example: "10,000" → "10000" (makes it usable as a number)
+
+ Number(...):
+
+ Converts the resulting string "10000" into the actual number 10000
+
+
+

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

@@ -6,20 +6,52 @@ const totalMinutes = (movieLength - remainingSeconds) / 60;
 const remainingMinutes = totalMinutes % 60;
 const totalHours = (totalMinutes - remainingMinutes) / 60;
 
+// Rename result to formattedTime for clarity
+
+const formattedTime = `${totalHours}:${remainingMinutes}:${remainingSeconds}`;
+console.log(formattedTime);
+
 const result = `${totalHours}:${remainingMinutes}:${remainingSeconds}`;
 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:
+// movieLength, [line 1]
+// remainingSeconds, [line 3]
+// totalMinutes, [line 4]
+// remainingMinutes, [line 6]
+// totalHours, [line 7]
+// result. [line 9]
+
 // b) How many function calls are there?
 
+// There is 1 function call:
+// console.log() 
+
 // c) Using documentation, explain what the expression movieLength % 60 represents
 // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators
 
+// The % operator is the remainder operator.
+// movieLength % 60 gives the remainder after dividing movieLength by 60,
+// which represents the leftover seconds after counting full minutes.
+
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
 
+// totalMinutes calculates how many whole minutes are in movieLength by
+// subtracting leftover seconds and dividing the remainder by 60.
+
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
 
+// Result is the movie length formatted as "hours:minutes:seconds".
+// A better name could be formattedTime.
+
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+
+// 1. The code correctly converts movieLength into hours, minutes, and seconds for positive values.
+// 2. It doesn’t handle zero or negative values properly—these cases need extra checks.
+// 3. Minutes and seconds may appear without leading zeros.
+
+

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

@@ -24,4 +24,29 @@ console.log(`£${pounds}.${pence}`);
 // Try and describe the purpose / rationale behind each step
 
 // To begin, we can start with
-// 1. const penceString = "399p": initialises a string variable with the value "399p"
+// 1. const penceString = "399p": initialises a string variable with the value "399p". The trailing "p" indicates the unit
+
+
+
+//2. Removes the"p" at the end of the string.
+To isolate the numeric part 
+
+//3. const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");
+
+//Pad the numeric string with leading zeros to ensure it has at least 3 digits
+
+//4.const pounds = paddedPenceNumberString.substring(
+  0,
+  paddedPenceNumberString.length - 2
+);
+//Extract the pounds part by taking all but the last two digits
+
+//5.Extract the pence part by taking the last two digits and pad with trailing zero if needed
+const pence = paddedPenceNumberString
+.substring(paddedPenceNumberString.length - 2)
+.padEnd(2, "0");
+
+// 6. Output the formatted price in pounds and pence
+console.log(`£${pounds}.${pence}`);
+
+// This program takes a string representing a price in pence

Sprint-1/4-stretch-explore/chrome.md

@@ -11,8 +11,15 @@ In the Chrome console,
 invoke the function `alert` with an input string of `"Hello world!"`;
 
 What effect does calling the `alert` function have?
+// i run alert("Hello World!");
+// A box pop up in the browser window with the message:Hello World!
+//It has an "OK" button that i must click to dismiss the alert
 
 Now try invoking the function `prompt` with a string input of `"What is your name?"` - store the return value of your call to `prompt` in an variable called `myName`.
 
 What effect does calling the `prompt` function have?
 What is the return value of `prompt`?
+
+ //const myName = prompt("What is your name?");
+ //a modal box appears with the message "What is your name?"
+ //there are OK AND Cancel buttons

Sprint-1/4-stretch-explore/objects.md

@@ -6,11 +6,26 @@ Open the Chrome devtools Console, type in `console.log` and then hit enter
 
 What output do you get?
 
-Now enter just `console` in the Console, what output do you get back?
+//ƒ log() { [native code] }
 
+Now enter just `console` in the Console, what output do you get back?
+//console {debug: ƒ, error: ƒ, info: ƒ, log: ƒ, warn: ƒ, …}
 Try also entering `typeof console`
 
+//object
+
 Answer the following questions:
 
 What does `console` store?
+
+// it stores tools to show messages in the browser's console
+
 What does the syntax `console.log` or `console.assert` mean? In particular, what does the `.` mean?
+
+//The . is the property accessor operator in JavaScript. It’s used to access properties or methods on an object. Here:
+
+console is the object.
+
+log or assert is a property of that object (specifically, a method/function).
+
+So, console.log means: “Access the log method on the console object.”

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

@@ -1,13 +1,20 @@
 // Predict and explain first...
 //  =============> write your prediction here
 
+// The code will throw an error because the variable `str` is being declared twice in the same scope.
+
 // call the function capitalise with a string input
 // interpret the error message and figure out why an error is occurring
 
+
 function capitalise(str) {
   let str = `${str[0].toUpperCase()}${str.slice(1)}`;
   return str;
 }
+capitalise("hello,this is a test");
+
+//
 
 // =============> write your explanation here
 // =============> write your new code here
+//// The error occurs because the variable `str`is declared twice in the same scope,which is not allowed in JavaScript.

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

@@ -2,6 +2,8 @@
 
 // Why will an error occur when this program runs?
 // =============> write your prediction here
+//Decimal number is undefined
+//we ll got syntax error as we are declaring a new variable
 
 // Try playing computer with the example to work out what is going on
 
@@ -18,3 +20,11 @@ console.log(decimalNumber);
 
 // Finally, correct the code to fix the problem
 // =============> write your new code here
+function convertToPercentage(decimalNumber) {
+
+    const percentage = `${decimalNumber * 100}%`;
+
+    return percentage;
+   }
+
+   result = console.log(convertToPercentage(0.5));

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

@@ -5,16 +5,28 @@
 
 // =============> write your prediction of the error here
 
+//we will get an error bcs the parameter of the function need to string type not number so it can be something like num
+
 function square(3) {
     return num * num;
 }
 
 // =============> write the error message here
+//Output:
+
+/index.js:1
+function square(3) {
+                ^
 
+SyntaxError: Unexpected number
 // =============> explain this error message here
 
 // Finally, correct the code to fix the problem
 
 // =============> write your new code here
 
-
+//THe error message tells that we wrote a syntax that JavaScript does not understand.
+function square(num) {
+    return num * num;
+}
+result = console.log(square(3));

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

@@ -1,9 +1,15 @@
 // Predict and explain first...
 
 // =============> write your prediction here
-
+// What I predict is that the console.log which is outside the function will pass the parameters 10 and 32 to the function
+// Then the console.log(a * b) which is inside the function will print out 
+ // to the terminal the multiplication of a by b
 function multiply(a, b) {
-  console.log(a * b);
+  const multiplicationResult =  (a * b);
+  return multiplicationResult;
+
+
+
 }
 
 console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);