ITP | SAMI SARDARZAI | Module-Structuring-and-Testing-Data | WEEK 2

Sprint-1/errors/0.js

@@ -1,2 +1,5 @@
-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?
+
+
+// by adding comment we can slove this problem

Sprint-1/errors/1.js

@@ -1,4 +1,7 @@
 // trying to create an age variable and then reassign the value by 1
 
-const age = 33;
-age = age + 1;
+// const age = 33;
+// age = age + 1;
+
+var age =23;
+age =1;

Sprint-1/errors/2.js

@@ -1,5 +1,12 @@
 // 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}`);
+/*Answer : The problem is that cityOfBirth is used before it’s defined.
+ JavaScript runs code from top to bottom, so when console.log tries to use cityOfBirth, it hasn’t been set yet*/
+
+// console.log(`I was born in ${cityOfBirth}`);
 const cityOfBirth = "Bolton";
+// const myWord= `I was born in ${cityOfBirth}`;
+// console.log(myWord);
+
+console.log(`I was born in ${cityOfBirth}`);

Sprint-1/errors/3.js

@@ -1,9 +1,17 @@
 const cardNumber = 4533787178994213;
-const last4Digits = cardNumber.slice(-4);
+// 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
+
+const last4Digits = cardNumber.toString().slice(-4);
+
+console.log(last4Digits);
+
+/* Prediction
+The code won’t work because cardNumber is a number, and .slice() only works on strings and arrays.
+To fix this, we need to turn cardNumber into a string first. */

Sprint-1/errors/4.js

@@ -1,2 +1,4 @@
-const 12HourClockTime = "20:53";
-const 24hourClockTime = "08:53";
+const HourClockTime = "20:53";
+const hourClockTime = "08:53";
+
+//we can not use number as a variable name !

Sprint-1/exercises/count.js

@@ -4,3 +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 increases count by 1. The = sets count to its new value.
+console.log(count);

Sprint-1/exercises/decimal.js

@@ -7,3 +7,10 @@ const num = 56.5678;
 // Create a variable called roundedNum and assign to it an expression that evaluates to 57 ( num rounded to the nearest whole number )
 
 // Log your variables to the console to check your answers
+
+const wholeNumberPart = Math.floor(num);
+console.log(wholeNumberPart);
+const decimalPart = num -wholeNumberPart;
+console.log(decimalPart);
+const roundedNum = Math.round(num);
+console.log(roundedNum);

Sprint-1/exercises/initials.js

@@ -4,3 +4,6 @@ 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 = firstName.charAt(0)+middleName.charAt(0)+lastName.charAt(0);
+console.log(initials);

Sprint-1/exercises/paths.js

@@ -12,7 +12,13 @@
 const filePath = "/Users/mitch/cyf/Module-JS1/week-1/interpret/file.txt";
 const lastSlashIndex = filePath.lastIndexOf("/");
 const base = filePath.slice(lastSlashIndex + 1);
+const dir = filePath.slice(0, lastSlashIndex);
+const dotIndex = base.lastIndexOf(".");
+const ext = base.slice(dotIndex);
+
 console.log(`The base part of ${filePath} is ${base}`);
+console.log(`The dir part of ${filePath} is ${dir}`);
+console.log(`The ext part of ${filePath} is ${ext}`);
 
 // Create a variable to store the dir part of the filePath variable
 // Create a variable to store the ext part of the variable

Sprint-1/exercises/random.js

@@ -2,7 +2,7 @@ const minimum = 1;
 const maximum = 100;
 
 const num = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum;
-
+console.log(num);
 // In this exercise, you will need to work out what num represents?
 // 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

Sprint-1/interpret/percentage-change.js

@@ -2,12 +2,12 @@ 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;
 
-console.log(`The percentage change is ${percentageChange}`);
+console.log(`The percentage change is ${percentageChange} %`);
 
 // Read the code and then answer the questions below
 
@@ -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?
+
+
+/*
+a) There are 4 function calls in total:
+   1. carPrice.replaceAll(",", "")
+   2. priceAfterOneYear.replaceAll(",", "")
+   3. Number(...) (used in two places)
+
+b) The error occurs on the line where priceAfterOneYear is reassigned.
+   Reason: Missing comma in the replaceAll function call. 
+   Fix: Correct it to priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", ""));
+
+c) Variable reassignment statements:
+   1. carPrice = Number(carPrice.replaceAll(",", ""));
+   2. priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", ""));
+
+d) Variable declaration statements:
+   1. let carPrice = "10,000";
+   2. let priceAfterOneYear = "8,543";
+   3. const priceDifference = carPrice - priceAfterOneYear;
+   4. const percentageChange = (priceDifference / carPrice) * 100;
+
+e) The expression Number(carPrice.replaceAll(",", "")):
+   - Removes commas from the carPrice string and converts it to a number.
+   - Purpose: To get a numerical value from the string for calculations.
+*/

Sprint-1/interpret/time-format.js

@@ -22,3 +22,11 @@ console.log(result);
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
 
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+
+// Answers:
+// a) There are 5 variable declarations: movieLength, remainingSeconds, totalMinutes, remainingMinutes, totalHours
+// b) There is 1 function call: console.log()
+// c) movieLength % 60 finds leftover seconds that don’t fit into a full minute
+// d) totalMinutes gives the number of complete minutes by removing extra seconds
+// e) result is the formatted time (HH:MM:SS); a better name could be formattedTime
+// f) Code works for any non-negative movieLength, but not for negative values

Sprint-1/interpret/to-pounds.js

@@ -1,21 +1,31 @@
-const penceString = "399p";
+const penceString = "399p"; // Initialize a string variable with the value "399p", which represents 399 pence.
 
-const penceStringWithoutTrailingP = penceString.substring(
-  0,
-  penceString.length - 1
-);
+// Remove the trailing 'p' from the string
+const penceStringWithoutTrailingP = penceString.substring(0, penceString.length - 1); 
+// This line uses the substring method to take all characters from the start up to (but not including) the last character 'p'.
+// The result will be "399".
 
-const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");
-const pounds = paddedPenceNumberString.substring(
-  0,
-  paddedPenceNumberString.length - 2
-);
+// Pad the pence number string to ensure it has at least 3 digits
+const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0"); 
+// This line ensures that the string has a minimum length of 3 characters, adding leading zeros if necessary.
+// For example, "5" would become "005", but "399" stays as "399".
 
+// Extract the pounds part from the padded pence string
+const pounds = paddedPenceNumberString.substring(0, paddedPenceNumberString.length - 2); 
+// This line takes all characters except the last two, which represent the pence.
+// For "399", it results in "3", meaning 3 pounds.
+
+ // Extract the pence part from the padded pence string
 const pence = paddedPenceNumberString
-  .substring(paddedPenceNumberString.length - 2)
-  .padEnd(2, "0");
+  .substring(paddedPenceNumberString.length - 2) // Get the last two characters, which represent the pence.
+  .padEnd(2, "0"); // Ensure that there are always two digits in the pence part, adding a zero if necessary.
+// For "399", this gives "99". If it were "5", it would give "05".
+
+// Print the final formatted price in pounds
+console.log(`£${pounds}.${pence}`); 
+// This line combines pounds and pence into a string formatted as "£3.99".
+// It uses template literals to insert the pound and pence values into the string.
 
-console.log(`£${pounds}.${pence}`);
 
 // This program takes a string representing a price in pence
 // The program then builds up a string representing the price in pounds

Sprint-2/debug/0.js

@@ -1,7 +1,19 @@
 // Predict and explain first...
 
 function multiply(a, b) {
+  // This function calculates the product of two numbers a and b.
+  // It logs the result (a * b) to the console but does not return anything.
   console.log(a * b);
 }
 
+
+// Here, we are calling the multiply function with 10 and 32.
+// The function will log the result (320) to the console.
 console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
+
+
+// However, the multiply function does not return a value. 
+// So, ${multiply(10, 32)} becomes undefined.
+// The final output of this console.log will be:
+// 1. First, 320 is printed from the multiply function.
+// 2. Then, "The result of multiplying 10 and 32 is undefined" is printed.

Sprint-2/debug/1.js

@@ -1,8 +1,15 @@
 // Predict and explain first...
 
 function sum(a, b) {
-  return;
-  a + b;
+   // The function has a 'return;' statement, which exits the function immediately.
+  // The line 'a + b' is ignored because it is placed after the 'return;' statement.
+  return; // The function ends here and returns undefined.
+  a + b; // This code is unreachable and will not execute.
 }
 
+// Here, we call the sum function with 10 and 32.
+// Since the function returns undefined, the result in the template literal will be undefined.
 console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
+
+// Output:
+// "The sum of 10 and 32 is undefined"

Sprint-2/debug/2.js

@@ -1,14 +1,59 @@
 // Predict and explain first...
 
+// Declare a constant `num` with the value 103
 const num = 103;
 
+// Define a function `getLastDigit()` which is intended to return the last digit of a number.
 function getLastDigit() {
+  // Convert `num` to a string and use `slice(-1)` to get the last character of the string.
+  // But `num` is always 103, so this will always return '3' regardless of the argument passed.
   return num.toString().slice(-1);
 }
 
+// Log the result of calling `getLastDigit(42)`
+// The function doesn't use the argument 42 and will always return '3' (from `num` = 103).
 console.log(`The last digit of 42 is ${getLastDigit(42)}`);
+
+// Log the result of calling `getLastDigit(105)`
+// The function doesn't use the argument 105 and will always return '3'.
 console.log(`The last digit of 105 is ${getLastDigit(105)}`);
+
+// Log the result of calling `getLastDigit(806)`
+// The function doesn't use the argument 806 and will always return '3'.
 console.log(`The last digit of 806 is ${getLastDigit(806)}`);
 
+
 // This program should tell the user the last digit of each number.
 // Explain why getLastDigit is not working properly - correct the problem
+
+
+// Explanation:
+// The original function was using a fixed constant `num` to get the last digit, 
+// which meant that it always returned the last digit of `103`, no matter 
+// what number was passed to the function.
+// To fix this, we need to update the function to accept a number as an argument 
+// and use that argument to extract the last digit.
+
+// Updated Function to Get Last Digit:
+function getLastDigit(num) {
+  // Convert the number to a string and use `slice(-1)` to extract the last digit.
+  // We now use the `num` passed as an argument to the function.
+  return num.toString().slice(-1); // This will correctly return the last digit of the number passed.
+}
+
+// Logging the results for different numbers:
+
+// Call the function with 42
+// The function should return '2' as it's the last digit of 42
+console.log(`The last digit of 42 is ${getLastDigit(42)}`);  // Expected Output: 2
+
+// Call the function with 105
+// The function should return '5' as it's the last digit of 105
+console.log(`The last digit of 105 is ${getLastDigit(105)}`);  // Expected Output: 5
+
+// Call the function with 806
+// The function should return '6' as it's the last digit of 806
+console.log(`The last digit of 806 is ${getLastDigit(806)}`);  // Expected Output: 6
+
+
+//NOTE : please comment first code if you want to run my codes ..

Sprint-2/errors/0.js

@@ -3,7 +3,17 @@
 // call the function capitalise with a string input
 // interpret the error message and figure out why an error is occurring
 
+// Function to capitalize the first letter of the string
 function capitalise(str) {
-  let str = `${str[0].toUpperCase()}${str.slice(1)}`;
-  return str;
+  // Problem: We can't redeclare 'str' inside the function as it's already a parameter
+  // Fix: Instead of redeclaring, we just modify the existing 'str' variable directly.
+
+  // let str = `${str[0].toUpperCase()}${str.slice(1)}  // we should remove the Let 
+
+  str = `${str[0].toUpperCase()}${str.slice(1)}`; 
+   // Capitalize the first letter and combine with the rest of the string
+
+  return str;  // Return the modified string
 }
+
+console.log(capitalise("coding"));  // Expected Output: "Coding"

Sprint-2/errors/1.js

@@ -3,11 +3,16 @@
 // Why will an error occur when this program runs?
 // Try playing computer with the example to work out what is going on
 
-function convertToPercentage(decimalNumber) {
-  const decimalNumber = 0.5;
-  const percentage = `${decimalNumber * 100}%`;
 
+// Function to convert decimal to percentage
+function convertToPercentage(decimalNumber) {
+  // const decimalNumber = 0.5;
+  // Removed the redeclaration of decimalNumber and just use the parameter
+  const percentage = `${decimalNumber * 100}%`;  // Convert the decimal to percentage
+
   return percentage;
 }
 
-console.log(decimalNumber);
+// Now we pass a decimal number as an argument to the function
+console.log(convertToPercentage(0.5));  // Expected Output: "50%"
+

Sprint-2/errors/2.js

@@ -3,8 +3,22 @@
 
 // this function should square any number but instead we're going to get an error
 
-function square(3) {
-    return num * num;
-}
+// function square(3) {
+//     return num * num;
+// }
 
 
+// The original function is incorrect because:
+// 1. The function parameter is written as `3`, which is a value, not a valid parameter name.
+// 2. Inside the function, the variable `num` is referenced, but it has not been defined anywhere, causing a ReferenceError.
+
+function square(number) {
+    // Now, instead of `3`, we have a valid parameter name `number`.
+    // The function will take `number` as input and return `number * number` (the square of the number).
+
+    return number * number;  // Multiply the number by itself to square it.
+  }
+
+  // Testing the function by passing the value `3` to it
+  console.log(square(3));  // Expected Output: 9
+