JavaScript problems & coding solution:

DOM Project js:

🔥 bd-phone

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🔥Interview-Questions-code:

📂 js-milestone123456

📂 HandNotes-PDF

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Click ⭐if you like the project. Pull Requests are highly appreciated. Follow me @BappaSaha for technical updates.

📂 Folder Structure:

📂 00-DOM-js

📂 01-Advanced-level-js

📂 02-Calculations codes

📂 03-js-map-find-filter-destructing

📂 04-javaScriptBasic-LWS

Questions:

0. object-destructuring

1. Console Log

2. Apply javaScript Concepts

3. While Loop & for loop:

    1.print a number from 0 to 10
    2.print a number from 1 to 10
    3.print the even number from 0 -20
    4. print the odd number from 0-20
   

4. Write a function-->function1.js

    1. wite a function having no parametaer.
    2. A function havig input parameters.
    3. A fucntion havng a return value
   

5. Simple calculation using function:

6. Factorial code

7. Declear Objects and its property

8. Mathe and rdandom number code -> mathe.js

9. swap variable / swap without temp/ desturting--> swap.js

10. Find the max number from the inputs (i code it three ways)-->max-number.js

11. Find the min number from the(2/3) inputs --> min-number.js

12. Array Related problem --> sum-array.js

    1. Sum of array using for loop-->sum-array.js
    2. Sum of array using function-->sum-array.js
    3. Find the largest number of an array -->largest-element.js
    4. Find the smallest elements of an array -->smallest-element.js
    

[Go to top:arrow_up: ](#top) ## 00.Map-Filter-Find

const products = [
  { id: 1, name: "water-bottol", price: 50, color: "yellow" },
  { id: 2, name: "pen-bottol", price: 507, color: "black" },
  { id: 3, name: "cock-bottol", price: 503, color: "black" },
  { id: 4, name: "soft-bottol", price: 506, color: "red" },
  { id: 5, name: "note-bottol", price: 507, color: "pink" },
];

//TODO: map
console.log("Map:--------->");
const product = products.map((product) => console.log(product));
const productName = products.map((p) => p.name);
// console.log(productName)

console.log("Filter:-------->");
//TODO: filter

const price = products.filter((product) => product.price > 506);
const blacks = products.filter((p) => p.color === "black");
console.log(blacks);
// console.log(price)

//TODO: find
console.log("Find:-------->");
const id = products.find((pId) => pId.id === 2);
console.log(id);

1.Apply javaScript Concepts

    >> Data tyes
    >> Variables
    >> Conditions
    >> Array
    >> Function
    >> Loop

[Data Types] :

There are 2 types of data-types:
1.Primitive : (stack)-->
    [string,numbers, boolean ,null,undifine, symbol]

2.Referance: (heap)-->
    [Arrays,object literals,functions, dates]

    => It works dinnamically means , we don't need to write the     datatype.

primitive data types :_

console.log('"Primitive data types"')

String :

let bname = "bappa";
var sname = " saha";
console.log("my string is :" + bname);
console.log("Data type is :" + typeof bname);

Numbers :

let num = 32;
console.log("number is : " + num);
console.log("Data type is :" + typeof num);

Boolean:

let isPlayer = true;
console.log("Bappa is a player ");
console.log(isPlayer);
console.log("Data type is :" + typeof isPlayer);

Null :

let nullVar = null;
console.log(nullVar);
console.log("Data type is :" + typeof nullVar);

Undefined :

let undef = undefined;
console.log(undef);
console.log("Data type is :" + typeof undef);

Reference data types :

console.log(' "Referance data types" ');

Array :

myarr = [1, 2, 3, 4, 5, false, "string"];
console.log(myarr);
console.table(myarr);
console.log("Data type is :" + typeof myarr);

Object literals :

let marks = {
bappa: 90,
doll: 91,
burii: 23,
' mis mayaboti': 44
}

console.log(marks);
console.log("Data type is :" + (typeof marks));

function findName(params) {

}
console.log("Data type is :" + (typeof findName));

let date = new Date();
console.log("Data type is :" + (typeof date));
</a>

[Variables] :

Variables in JavaScript :

There are threee types of variables in javascript. They all are keywords.

01.var type(global),
02.const type(local ),
03.let type.(block level scope)

                // var type: global
                // var used in old javascript

var nam = `'coder'bappa.`;
console.log(nam);

var youtube;
youtube = "gogabappa";
console.log(youtube);

var marks = 46;
var mark = "46";
console.log("this is value not string  ", marks);
console.log(nam, youtube, marks, mark);

Rules:

 --> Rules for creating javascript variables:
       01. can not start with numbers.
       02. can start with letters, underscore(_), dollars($).
       03. Case-sensitive.
            i.camelCase
            ii.kabab-case
            iii.snake_case
            iv.PascalCase

Examples:

var city = "Dhaka";
console.log(city);
var _city1 = "Dhaka"; //not used in morder javascript.
var $city2 = "Dhaka"; //not used in morder javascript.

// const variable : local

// const variable : where the value is fixed
//  Assignment to constant variable is not allowed in const type
// when makimg const , we have to initialize it .

const fName = " bappa";
fName = "saha"; // Uncaught TypeError: Assignment to constant variable.
console.log(fName);

//let variable: block level scope

// let used in moder javascipt replacement of var .
{
  let city = "Thakurgaon";
  console.log(city); // output:Thakurgaon
  city = "khulna";
  console.log(city); // output:khulna
}
console.log(city); // output:Dhaka

// some cool things of array
const array1 = [11, 22, 33, 44, "bappa"];
array1.push(55);
console.log(array1); // [11, 22, 33, 44, "bappa", 55]
array1.pop();
console.log(array1); //  [11, 22, 33, 44, "bappa"]

2. While Loop| & for loop:

    1.print a number from 0 to 10
    2.print a number from 1 to 10
    3.print the even number from 0 -20
    4. print the odd number from 0-20

3. Write a function:

    1. wite a function having no parametaer.
    2. A function havig input parameters.
    3. A fucntion havng a return value

4. Simple calculation using function:

    1.Addition|Slubtraction|Multiplication|Division numbers.
    2. Unit Convert Inch to feet , miles to kilometers
    3.Cheeck odd or even number using a function

5. Calculate factorial in various way:

    1.Calculate Factorial number using for loop
    2.Calculate Factorial number using function
    3. Calculate Factorial using decremental loop
    4.Calculate Factorial in recursive function

## 6. Declear Objects and its property:

    1. Declear & Access  a object .
    2. Different ways to set a object property of an object.

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_ --> All About Console Log <-- _

single line Comment (ctr + /)

multiline comment (shift + alt + A)

1.How to print anythinig in console log:

Console log means : console এ লিখে দাও যেইভাবে লিখা আছে সেইভাবেই। JavaScript is a forgiven language .

console.log('"This is console.log tutorial by coder bappa"');
console.time("my code took time:");
console.log("with out using semicolon");
console.log("using semicolon ");
console.log(10 + 10);
console.log(34); //mathematics operation
console.log(true); //boolen variable

2. write string in javaScript

console.log("using double quotation");
console.log("using single quotation");
console.log('"using double quotation under single quotation"');
console.log(`backtag <h1> <h1/>`);

3. console log Array

console.log([11, 22, 33, 44]);

4. console log e Object lock করতে পারি চাইলে

console.log({ bappa: "coder bappa", age: "25" });
console.table({ bappa: "coder bappa", age: "25" });
console.warn("this is a warning");

console.timeEnd("my code took time:");
console.assert(500 < 179, "Age > 179 is not possible ");
console.error("this is an error");

5. console.clear();

console.time("my code took time:");
console.timeEnd("my code took time:");

_ --> Factorial code <-- _

/*
    Basic  of Factorial (!)
 1! = 1
 2! = 2 X 1  = 2 X 1!
 3! = 3 X 2 X 1 = 3 X 2!
 4! = 4 X 3 X 2 X 1
 5! = 5 X 4 X 3 X 2 X 1
 6! = 6 X 5 X 4 X 3 X 2 X 1
 7! = 7 X 6 X 5 X 4 X 3 X 2 X 1
 7! = 7 X 6!
 n! = n X 9(n-1)!


*/

1. Calculate Factorial number using for loop:

       Output is : 120

var factorial = 1;
for (var i = 1; i <= 5; i++) {
  factorial = factorial * i;
}
console.log(factorial);

2. Calculate Factorial number multiple time using function:

   Output is :    The factorial of 7 is: 5040

function getFactorial(number) {
  let factorial = 1;
  for (let i = 1; i <= number; i++) {
    factorial = factorial * i;
  }
  return factorial;
}

let givenNumber = getFactorial(7);
console.log("The factorial of 7 is:", givenNumber);

3. .Calculate Factorial using decremental loop:

   Output is :    The factorial of 6 is: 720

function getFactorial(number) {
  let factorial = 1;
  for (let i = number; i >= 1; i--) {
    factorial = factorial * i;
  }
  return factorial;
}

let givenNumber = getFactorial(6);
console.log("The factorial of 6 is:", givenNumber);

4. .Calculate Factorial using recursive function :

   Output is : Factorial is:  120

function factorial(n) {
  if (n == 1) {
    return 1;
  }
  return n * factorial(n - 1);
}

const myFactorial = factorial(5);
console.log("Factorial is: ", myFactorial);

Swap variable:

output is:
Before swapping:  5 7
After swapping:  7 5

let first = 5;
let second = 7;
console.log("Before swapping: ", first, second);

var temp = first;
first = second;
second = temp;
console.log("After swapping: ", first, second);
</a>

Using destructing:

output is:
Before swapping:  10 40
After swapping:  40 10

var first = 10;
var second = 40;
console.log("Before swapping: ", first, second);

// Array Distructing
[first, second] = [second, first];
console.log("After swapping: ", first, second);