northwest |Rahwa Zeslus |module-structure-and-Testing-Data|week2

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?
+We don't want the computer to run these 2 lines - how can we solve this problem?
+console.log()
+//SyntaxError: Unexpected identifier
+//It misses certain of java script structure like keywords ,variables and functions

Sprint-1/errors/1.js

@@ -2,3 +2,6 @@
 
 const age = 33;
 age = age + 1;
+console.log(age)
+//TypeError: Assignment to constant variable.
+    //he const keyword is initialized once,can not change or update the constant variable twice

Sprint-1/errors/2.js

@@ -3,3 +3,5 @@
 
 console.log(`I was born in ${cityOfBirth}`);
 const cityOfBirth = "Bolton";
+// ReferenceError: Cannot access 'cityOfBirth' before initialization
+//this occurs when it is attempted to access the variable before declaring it with in that scope ,so "const cityOfBirth = "Bolton"; should come first.

Sprint-1/errors/3.js

@@ -1,9 +1,15 @@
 const cardNumber = 4533787178994213;
-const last4Digits = cardNumber.slice(-4);
+const last4Digits = cardNumber.toString().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
+console.log(last4Digits);
+//TypeError: cardNumber.slice is not a function
+//the error is occured because cardNumber variable stored a number not a string ,this was as I predicted
+//in order to make this string I add toString function to change it to string under the colon
+//root@acer:~/CYF/Module-Structuring-and-Testing-Data/Sprint-1/errors# node 3.js
+//4213

Sprint-1/errors/4.js

@@ -1,2 +1,6 @@
 const 12HourClockTime = "20:53";
-const 24hourClockTime = "08:53";
+console.log(12HourClockTime)
+const 24hourClockTime = "08:53";
+console.log(24HourClockTime)
+//SyntaxError: Invalid or unexpected token
+//Since the variable starts with number it returns SyntaxError. In java script variables can not start with number.

Sprint-1/exercises/count.js

@@ -4,3 +4,5 @@ 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
+      // the count is being increamented by one , and the initial value is 0
+console.log(count)

Sprint-1/exercises/decimal.js

@@ -3,7 +3,15 @@ const num = 56.5678;
 // You should look up Math functions for this exercise https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math
 
 // Create a variable called wholeNumberPart and assign to it an expression that evaluates to 56 ( the whole number part of num )
+let wholeNumberPart = Math.floor(num);
+console.log(wholeNumberPart);
 // Create a variable called decimalPart and assign to it an expression that evaluates to 0.5678 ( the decimal part of num )
+let decimalPart = (num%1).toFixed(4)
+console.log(decimalPart)
 // Create a variable called roundedNum and assign to it an expression that evaluates to 57 ( num rounded to the nearest whole number )
-
+roundedNum=Math.round(num);
+console.log(roundedNum);
 // Log your variables to the console to check your answers
+
+
+

Sprint-1/exercises/initials.js

@@ -4,3 +4,5 @@ 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.slice(0,1) + middleName.slice(0,1) +  lastName.slice(0,1)
+console.log(initials)

Sprint-1/exercises/paths.js

@@ -15,4 +15,8 @@ const base = filePath.slice(lastSlashIndex + 1);
 console.log(`The base part of ${filePath} is ${base}`);
 
 // Create a variable to store the dir part of the filePath variable
+let dirPart = filePath.slice(7,44)
+console.log(dirPart)
 // Create a variable to store the ext part of the variable
+let extPart = filePath.slice(-4)
+console.log(extPart)

Sprint-1/exercises/random.js

@@ -4,6 +4,31 @@ const maximum = 100;
 const num = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum;
 
 // In this exercise, you will need to work out what num represents?
+  //Math.floor(Math.random() * (maximum - minimum + 1)) + minimum
+  //Math.floor(Math.random() * (100 - 1 + 1)) + 1
+  //Math.floor(Math.random() * (100)) + 1
+  //Math.floor(0.1812 * (100)) + 1
+  //Math.floor(18.12) + 1
+  //18 + 1
+  //19=this could be change as the Math.random() function could returns any random value
 // Try breaking down the expression and using documentation to explain what it means
+  //Math.random()= returns a random value between 0 and 1
+  //minimum and maximum variables are already assigned to the values 1 and 100 respectively
 // 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
+// root@acer:~/CYF/Module-Structuring-and-Testing-Data/Sprint-1/exercises# node random.js 
+// 73
+// root@acer:~/CYF/Module-Structuring-and-Testing-Data/Sprint-1/exercises# node random.js 
+// 40
+// root@acer:~/CYF/Module-Structuring-and-Testing-Data/Sprint-1/exercises# node random.js 
+// 73
+// root@acer:~/CYF/Module-Structuring-and-Testing-Data/Sprint-1/exercises# node random.js 
+// 99
+// root@acer:~/CYF/Module-Structuring-and-Testing-Data/Sprint-1/exercises# node random.js 
+// 79
+// root@acer:~/CYF/Module-Structuring-and-Testing-Data/Sprint-1/exercises# node random.js 
+// 87
+// root@acer:~/CYF/Module-Structuring-and-Testing-Data/Sprint-1/exercises# node random.js 
+// 8
+// root@acer:~/CYF/Module-Structuring-and-Testing-Data/Sprint-1/exercises# 
+console.log(num)

Sprint-1/interpret/percentage-change.js

@@ -12,11 +12,22 @@ 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
-
+  //four functions
+    //carPrice = Number(carPrice.replaceAll(",", ""));
+    //priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ""));
+    //replaceAll(",", "")
+    //replaceAll("," "")
 // 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?
-
+   //line 5,the error is because of missing comma in replaceAll function
 // c) Identify all the lines that are variable reassignment statements
-
+  // const priceDifference = carPrice - priceAfterOneYear;
+  // const percentageChange = (priceDifference / carPrice) * 100;
 // d) Identify all the lines that are variable declarations
-
+     // let carPrice = "10,000";
+     // let priceAfterOneYear = "8,543";
+     // const priceDifference = carPrice - priceAfterOneYear;
+     // const percentageChange = (priceDifference / carPrice) * 100;
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+     //Number(carPrice.replaceAll(",","")) here ,It has two functions replaceAll() and Number 
+     //replaceAll() function removes all "," 
+     //Number function change the the string data to numeric

Sprint-1/interpret/time-format.js

@@ -1,4 +1,4 @@
-const movieLength = 8784; // length of movie in seconds
+const movieLength = 9999; // length of movie in seconds
 
 const remainingSeconds = movieLength % 60;
 const totalMinutes = (movieLength - remainingSeconds) / 60;
@@ -12,13 +12,33 @@ 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?
+  //Five
 
 // b) How many function calls are there?
+   //one
 
 // c) Using documentation, explain what the expression movieLength % 60 represents
-
+   //movieLength % 60  calculates the remainder ,that found by dividing 8784/60 
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
-
+  //const totalMinutes = (movieLength - remainingSeconds) / 60;
+        //movieLength  = 8784
+        //remainingSeconds = 24 
+             // = (8784-24)/60=8760/60=146
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
-
+       //`${totalHours}:${remainingMinutes}:${remainingSeconds}`
+       //formats the values of totalHours, remainingMinutes, and remainingSeconds into a time-like string in the format hours:minutes:seconds.
+       //durationTime=`${totalHours}:${remainingMinutes}:${remainingSeconds}`
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+  //yes!it works for all values
+         //root@acer:~/CYF/Module-Structuring-and-Testing-Data/Sprint-1/interpret# node time-format.js
+        // 2:26:24
+        // root@acer:~/CYF/Module-Structuring-and-Testing-Data/Sprint-1/interpret# node time-format.js
+        // 2:26:22
+        // root@acer:~/CYF/Module-Structuring-and-Testing-Data/Sprint-1/interpret# node time-format.js
+        // 2:26:0
+        // root@acer:~/CYF/Module-Structuring-and-Testing-Data/Sprint-1/interpret# node time-format.js
+        // 0:1:0
+        // root@acer:~/CYF/Module-Structuring-and-Testing-Data/Sprint-1/interpret# node time-format.js
+        // 0:0:20
+         // root@acer:~/CYF/Module-Structuring-and-Testing-Data/Sprint-1/interpret# node time-format.js
+        // 0:14:59

Sprint-1/interpret/to-pounds.js

@@ -25,3 +25,15 @@ console.log(`£${pounds}.${pence}`);
 
 // To begin, we can start with
 // 1. const penceString = "399p": initialises a string variable with the value "399p"
+
+ // 2.const penceStringWithoutTrailingP = penceString.substring( 0, penceString.length - 1);:it initializing the string from the start(index[0]) by excluding the last character therefore,the p will be excluded//399
+
+ //3.const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0"): padStart makes sure that paddedPenceNumberString is three characters long//399
+
+ //4.const pounds = paddedPenceNumberString.substring(  0, paddedPenceNumberString.length - 2):it initializing the string from the start(index[0]) by excluding the last two characters//3
+
+ //5.const pence = paddedPenceNumberString.substring(paddedPenceNumberString.length - 2) .padEnd(2, "0"):two functions here 
+
+   //the first one paddedPenceNumberString.substring(paddedPenceNumberString.length - 2) : This calculates the starting index for the substring, which is two characters from the end of the string//99
+   //the second one is padEnd(2, "0") which takes the last two characters of the string//99
+ //6. console.log(`£${pounds}.${pence}`): this takes the value pounds and pence to be returned.

Sprint-2/implement/bmi.js

@@ -1,3 +1,4 @@
+
 // Below are the steps for how BMI is calculated
 
 // The BMI calculation divides an adult's weight in kilograms (kg) by their height in metres (m) squared.
@@ -13,3 +14,16 @@
 // Given someone's weight in kg and height in metres
 // Then when we call this function with the weight and height
 // It should return their Body Mass Index to 1 decimal place
+
+
+
+function BMICalculation(height, adultWeight) {
+  // Calculate BMI
+  const heightSquared = height * height; 
+  const BMI = adultWeight / heightSquared;
+
+
+  return BMI.toFixed(1);
+}
+
+console.log(BMICalculation(1.5, 60)); 

Sprint-2/implement/to-pounds.js

@@ -4,3 +4,31 @@
 // You will need to declare a function called toPounds with an appropriately named parameter.
 
 // You should call this function a number of times to check it works for different inputs
+function toPounds(penceString) {
+
+  if (!penceString || !penceString.endsWith("P")||isNaN(penceString)) {
+    return "Invalid input. Please provide a valid pence amount";
+  }
+
+
+const penceStringWithoutTrailingP = penceString.substring(
+  0,
+  penceString.length - 1)
+
+
+const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");
+const pounds = paddedPenceNumberString.substring(
+  0,
+  paddedPenceNumberString.length - 2)
+
+
+const pence = paddedPenceNumberString
+  .substring(paddedPenceNumberString.length - 2)
+  .padEnd(2, "0");
+
+  return (`£${pounds}.${pence}`);
+}
+
+console.log(toPounds(""))
+
+

Sprint-2/implement/vat.js

@@ -8,3 +8,8 @@
 // Given a number,
 // When I call this function with a number
 // it returns the new price with VAT added on
+function priceWithoutVAT(price){
+    const priceWithVAT = price + (price * 0.2);
+    return priceWithVAT;
+  }
+  console.log (priceWithoutVAT(50));