NW6| Sabella -Fisseha| JS1 | Week4/Exercise

week-1/errors/0.js

@@ -1,2 +1,3 @@
-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?
+// we can comment out , the thing we don't want he computer to run it.

week-1/errors/1.js

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

week-1/errors/2.js

@@ -1,5 +1,5 @@
 // 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}`);
+// what's the error ? it started by asking for print before initializing the variable
 const cityOfBirth = "Bolton";
+console.log(`I was born in ${cityOfBirth}`);
+

week-1/errors/3.js

@@ -1,6 +1,6 @@
-const cardNumber = 4533787178994213;
+let cardNumber = "4533787178994213";
 const last4Digits = cardNumber.slice(-4);
-
+console.log(last4Digits)
 // The last4Digits variable should store the last 4 digits of cardNumber
 // However, the code isn't working
 // Make and explain a prediction about why the code won't work

week-1/errors/4.js

@@ -1,2 +1,3 @@
-const 12HourClockTime = "20:53";
-const 24hourClockTime = "08:53";
+const twelveHourClockTime = "20:53";
+const twentyfourHourClockTime = "08:53";
+// variable names cannot start with a number.

week-1/exercises/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
+// it is reassigning the variable to increase by 1

week-1/exercises/decimal.js

@@ -1,6 +1,11 @@
 
 const num = 56.5467;
-
+const wholeNumberPart = Math.trunc(num);
+const decimalPart = num % 1;
+const roundedNum = Math.round(num);
+console.log(decimalPart)
+console.log(wholeNumberPart)
+console.log(roundedNum)
 // 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 )

week-1/exercises/initials.js

@@ -1,6 +1,7 @@
 let firstName = "Creola";
 let middleName = "Katherine";
 let lastName = "Johnson";
-
+const initials = firstName.charAt(0)+ middleName.charAt(0) + lastName.charAt(0)
+console.log(initials)
 // Declare a variable called initials that stores the first character of each string in upper case to form the user's initials
 // Log the variable in each case

week-1/exercises/paths.js

@@ -11,8 +11,13 @@
 
 const filePath = "/Users/mitch/cyf/Module-JS1/week-1/interpret/file.txt";
 const lastSlashIndex = filePath.lastIndexOf("/");
+// console.log(lastSlashIndex);
 const base = filePath.slice(lastSlashIndex + 1);
 console.log(`The base part of ${filePath} is ${base}`);
+const dirPart = filePath.slice(0, lastSlashIndex);
 
+const extPart = filePath.slice(filePath.lastIndexOf(".")+1);
+console.log(`the ext part of  ${filePath}  ${extPart}`)
+console.log(`the dir part of  ${filePath}  ${dirPart}`)
 // Create a variable to store the dir part of the filePath variable
 // Create a variable to store the ext part of the variable

week-1/exercises/random.js

@@ -2,7 +2,11 @@ const minimum = 1;
 const maximum = 100;
 
 const num = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum;
-
+console.log(num)
+//  maximum- minimum + 1= 100
+// math.random * 100 = will be between [o, 100)
+// Math.floor[0,100) = [0, 99]
+// math.floor + minimum = [1,100]
 // 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

week-1/explore/chrome.md

@@ -8,11 +8,13 @@ Just like the Node REPL, you can input JavaScript code into the Console tab and
 Let's try an example.
 
 In the Chrome console,
-invoke the function `alert` with an input string of `"Hello world!"`;
-
+invoke the function `alert`with an input string of `"Hello world!"`;
+<!-- the chrome new tab page says "hello world" -->
 What effect does calling the `alert` function have?
 
 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`.
-
+<!-- it gives me an input to add a name, when I add "my name" my name apperared on the console -->
 What effect does calling the `prompt` function have?
+<!-- it brings a user input -->
 What is the return value of `prompt`?
+<!-- the return value is the value you add on the input -->

week-1/interpret/percentage-change.js

@@ -12,9 +12,19 @@ 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
-
+//    --> 5 function calls. 
+//    --> Number
+//    --> ReplceAll 
+//    --> Number 
+//    --> ReplaceAll
+//    --> percentageChange
 // b) Identify all the lines that are variable reassignment statements
-
+//      --> carPrice = Number()
+//     --> priceAfterOneYear = Number()
 // c) 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;
 // d) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+//      --> It replace all the commas to an empty string and the Number constructor is used to change the sting to numerical value

week-1/interpret/time-format.js

@@ -1,6 +1,6 @@
 const movieLength = 8784; // length of movie in seconds
 
-const remainingSeconds = movieLength % 60;
+const remainingSeconds = movieLength % 1.30;
 const totalMinutes = (movieLength - remainingSeconds) / 60;
 
 const remainingMinutes = totalMinutes % 60;
@@ -13,17 +13,21 @@ 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?
+// a) How many variable declarations are there in this program? 7
 
-// b) How many function calls are there?
+// b) How many function calls are there? 
+//     --> There is no function call.
 
 // c) Using documentation on MDN, explain what the expression movieLength % 60 represents
-
+//     --> It is the reminder of 8784 divided by 60.
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
-
-// e) What do you think the variable result represents? Can you think of a better name for this variable?
-
+//     --> Const totalMinutes = (movieLength - remainingSeconds) / 60; == it 8784 - 24(remaining of 8784/60) which is 8760/60 =146;
+// e) What do you think the variable result represents? Can you think of a better name for this variable? 
+//     --> totalResult, 
 // f) Think about whether this program will work for all values of movieLength.
 //    Think of what values may cause problems for the code.
 //    Decide the result should be for those values, then test it out.
 //    Can you find any values of movieLength which don't give you what you'd expect?
+//  --> Division by zero.
+//  --> Floating numbers (decimal).
+//  --> The result will be unknown.

week-1/interpret/to-pounds.js

@@ -26,4 +26,16 @@ console.log(`£${pounds}.${pence}`);
 
 // To begin, we can start with
 
-// 1. const penceString = "399p": initialises a string variable with the value "399p"
+// 1. const penceString = "399p": initializes a string variable with the value "399p"
+// 2. penceString.length = 4 : total number of count of a string.
+// 3. penceString.length - 1 = 3
+// 4. penceString.substring(0,penceString.length - 1); -> penceString.substring(0,3)
+// 5. penceString.substring(0,3); = 399: it selects character between (0,3) so it remove "p".
+// 6. penceStringWithoutTrailingP.padStart(3, "0"); : 399 has already 3 character and the padStart ask to add "o" upto having three digit.  
+// 7. paddedPenceNumberString = 399;
+// 8. paddedPenceNumberString.length - 2 = 1;
+// 9. pound = paddedPenceNumberString.substring( 0,1) = 3;
+// 10. paddedPenceNumberString.substring(paddedPenceNumberString.length - 2)--> paddedPenceNumberString.substring(3 - 2)
+// 11. 399.paddedPenceNumberString.substring(3 - 2)= 99;
+// 12. pence= 99.padEnd(2,"0")--> 99 has already 2 digit so no need to add "0";
+// 13. console.log(`£${pounds}.${pence}`);= 3.99;

week-2/debug/0.js

@@ -5,3 +5,5 @@ function multiply(a, b) {
 }
 
 console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
+// 320 and undefined because a and b are saved in the local scope not in global.
+//  If we put return instead of console inside the function it would work 

week-2/debug/1.js

@@ -6,3 +6,5 @@ function sum(a, b) {
 }
 
 console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
+// The sum will still be undefined.  
+// Because of the code error,we don't use semi-column after we wrote return,

week-2/debug/2.js

@@ -12,3 +12,4 @@ 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
+// It will be all 3, because we use a global scope declaration in to our local scope, it always read to it,instead of using the numbers we gave on the console

week-2/errors/0.js

@@ -2,8 +2,12 @@
 // write down the error you predict will be raised
 // then call the function capitalise with a string input
 // interpret the error message and figure out why it's happening, if your prediction was wrong
+// answer
+// It is not going to work.
+// str should not be declared as a variable since it is already a parameter for capitalise function.
 
 function capitalise(str) {
-  let str = `${str[0].toUpperCase()}${str.slice(1)}`;
+  str = `${str[0].toUpperCase()}${str.slice(1)}`;
   return str;
 }
+console.log(capitalise("anna"));

week-2/errors/1.js

@@ -2,12 +2,15 @@
 // Write down the error you predict will be raised
 // Why will an error occur when this program runs?
 // Play computer with the example to work out what is going on
+// it doesn't work
+// the code used decimal as a constant variable inside the function and again as a parameter.
+// If we take out the variable decimal inside the local scope and put it as global will make it work.
 
 function convertToPercentage(decimalNumber) {
-  const decimalNumber = 0.5;
+
   const percentage = `${decimalNumber * 100}%`;
 
   return percentage;
 }
-
+const decimalNumber = 0.5;
 console.log(decimalNumber);

week-2/errors/2.js

@@ -2,9 +2,13 @@
 // Predict and explain first...
 // this function should square any number but instead we're going to get an error
 // what is happening? How can we fix it?
-
-function square(3) {
+// answer
+// We can not use numbers as a parameter.
+// the function doesn't know 'num'
+// If we place "num" inside the parameter.
+// And place the constant variable outside the function, it will work.
+function square(num) {
     return num * num;
 }
-
-
+const result = square(3);
+console.log(result);

week-2/implement/bmi.js

@@ -13,3 +13,10 @@
 // Given someone's weight in kg and height in metres
 // When we call this function with the weight and height
 // Then it returns their Body Mass Index to 1 decimal place
+function bmi(weight,height){
+    if (weight <= 0 || height <= 0) { return "it is a wrong input";}
+    str = height*height;
+    calculate = weight/str
+    return calculate.toFixed(1)
+}
+console.log(bmi(70,1.73));

week-2/implement/cases.js

@@ -15,3 +15,12 @@
 
 // Come up with a clear, simple name for the function
 // Use the string documentation to help you plan your solution
+function capitalise(str){
+    words = str.split(" ");
+    camel = words.map(word => word.toUpperCase());
+    camelsnake = camel.join("_");
+  return camelsnake;
+}
+console.log(capitalise("lord of the rings"));
+console.log(capitalise("the great gatsby"));
+console.log(capitalise("the da vinci code"));

week-2/implement/to-pounds.js

@@ -3,3 +3,21 @@
 // Take this code and turn it into a reusable block of code.
 // Declare a function called toPounds with an appropriately named parameter.
 // Call this function a number of times to check it works for different inputs
+const penceString = "399p";
+
+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");
+
+console.log(`£${pounds}.${pence}`);

week-2/implement/vat.js

@@ -8,3 +8,8 @@
 // Given a number,
 // When I call this function with a number
 // Then it returns the new price with VAT added on
+function vat(p,v){
+
+    return p*v ;
+}
+console.log(vat(50,1.2));

week-2/interpret/time-format.js

@@ -26,18 +26,28 @@ console.log(formatTimeDisplay(143));
 // Questions
 
 // a) When formatTimeDisplay is called how many times will pad be called?
-
+//      3 times
 // Call formatTimeDisplay with an input of 143, now answer the following:
 
 // b) What value is assigned to the parameter num when pad is called for the first time?
-
+//  0
 // c) What is the return value of pad when it is called for the first time?
-
+// Answer = 00
+// function formatTimeDisplay(143) {
+  // const remainingSeconds = 143% 60; which is 23 remaining
+  // const totalMinutes = (143- 23) / 60; it will be 120/60 which is 2
+  // const remainingMinutes = 2% 60; which is 0
+  // const totalHours = (2- 0) / 60; which is 0.033
+  // const remainingHours = 0.033 % 24; which is 0
+
+  // return `${pad(0)}:${pad(0)}:${pad(
+  //   23
+  // )}`;
 // d) What is the value assigned to the parameter num when pad
 // is called for the last time in this program?  Explain your answer
-
+//  23
 // e) What is the return value when pad is called
 // for the last time in this program?  Explain your answer
-
+// 23
 // f) Research an alternative way of padding the numbers in this code.
 // Look up the string functions on mdn

week-4/implement/card-validator.js

@@ -0,0 +1,36 @@
+// Number must be 16 digits, all of them must be numbers.
+// - You must have at least two different digits represented (all of the digits cannot be the same).
+// - The final digit must be even.
+// - The sum of all the digits must be greater than 16.
+function addingCard(card) {
+    // typeof card === 'number' ;
+    const num = String(card).split("").map(Number);
+
+    let add = 0;
+
+    for (let i = 0; i < num.length - 1; i += 2) {
+        add += num[i] + num[i + 1];
+    }
+
+    return add;
+}
+
+function creditCard(card) {
+    const num = String(card).split("").map(Number);
+
+    if (num.length >= 16 && new Set(num).size >= 2 && addingCard(card) >= 16) {
+        return "card is valid";
+    } else {
+        return "card is not valid";
+    }
+}
+
+// console.log(creditCard('26287476788868563215'));
+test("check if card is valid", function () {
+    const card= '26287476788868563215';
+    const currentOutput = creditCard(card);
+    const targetOutput = "card is valid";
+
+    expect(currentOutput).toBe(targetOutput);
+
+});