Forem: Amit Prajapati

this keyword in js

Amit Prajapati — Tue, 02 Apr 2024 09:27:54 +0000

thiskeyword is very confusing many developers do not understand how this keyword works in deep!

use of map method in javascript

Amit Prajapati — Wed, 06 Sep 2023 04:39:26 +0000

map method return new array

let clothPrices = [350, 200, 500, 800]
let discountPercent = 10 //percent 

let discountedClothPrices =  clothPrices.map((price)=>{
    let amount = (price * discountPercent)/100;
    return (price - amount).toFixed(2);
})  

console.log(discountedClothPrices)

Reading file in nodejs with use of module fs and path

Amit Prajapati — Sun, 29 Jan 2023 15:32:37 +0000

Hi!

By asynchronously

const  fs = require("fs");
const path = require("path");

const fileUrl = path.join(__dirname, "test.txt");
fs.readFile(fileUrl,(err,data)=>{
    console.log("fileData: ",data)
});

By synchronously

const  fs = require("fs");
const path = require("path");

const fileUrl = path.join(__dirname, "test.txt");
const fileData = fs.readFileSync(fileUrl);
console.log(fileData )

What should be the output in javascript console ?

Amit Prajapati — Fri, 28 Oct 2022 11:41:30 +0000

 (1+2,2+6,5+5)

I was trying to put in chrome console.log to print the 10. I have not understood .why only 10 editions were gone 1+2 and 2+6 ??.

Preview how CSS border-radius values affect an element

Amit Prajapati — Thu, 28 Jul 2022 15:45:27 +0000

const container = document.querySelector('#container').style;
const left = document.querySelector('#left');
const tops = document.querySelector('#top');
const right = document.querySelector('#right');
const buttom = document.querySelector('#buttom');
window.addEventListener('click',(e)=>{
  container.borderLeft = `2px solid red`; 
  container.borderTopLeftRadius = Number(left.value)+'px'; 
})
window.addEventListener('click',(e)=>{
  container.borderRight = `2px solid #e91e63`; 
  container.borderTopRightRadius = Number(tops.value)+'px'; 
})
window.addEventListener('click',(e)=>{
  container.borderTop = `2px solid #673ab7`; 
  container.borderBottomLeftRadius = Number(right.value)+'px'; 
})
window.addEventListener('click',(e)=>{
  container.borderBottom = `2px solid #009688`;

  container.borderBottomRightRadius = Number(buttom.value)+'px'; 
})

*
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Write the program to convert the binary to decimal ?

Amit Prajapati — Fri, 15 Jul 2022 16:09:50 +0000

Binary is the number system all digital computers are based on. Therefore it's important for developers to understand binary, or base 2, mathematics. The purpose of Bin2Dec is to provide practice and understanding of how binary calculations
app.js

let decimal = document.getElementById('decimal');
let binary = document.getElementById('binary');
let error = document.getElementById('error');
let binaryNumber = '';
let maxInputLength = 10;
binary.addEventListener('keypress', (e) => {
  error.innerHTML = '';
  if (binaryNumber.length == maxInputLength) {
    error.innerHTML = `You can enter only ${maxInputLength} the length of the binary`;
    return e.preventDefault();
  }
  if (!(e.key == 0 || e.key == 1)) {
    error.innerHTML = 'Invalid key press';
    binaryNumber.replace(e.key, '', '');
    binary.value = binaryNumber;
    e.preventDefault();
    return false;
  }
  binaryNumber += e.key
  decimal.innerHTML = binaryNumber;
})
let count = 0;
let decimalNumber = 0;
window.addEventListener('click', (e) => {
  if (!binaryNumber.length) {
    return e.preventDefault();
  }
  for (let j = binaryNumber.length; j > 0; j--) {
    decimalNumber += Number(getDecimalNumber(j,Number(binaryNumber[count])))
    count++;
  }
  decimal.innerHTML = decimalNumber;
  decimalNumber = 0
})

function getDecimalNumber(count,binary) {
  let n = 0;
  switch (count) {
    case 1: n = binary ? 1 : 0; break;
    case 2: n = binary ? 2 : 0; break;
    case 3: n = binary ? 4 : 0; break;
    case 4: n = binary ? 8 : 0; break;
    case 5: n = binary ? 16 : 0; break;
    case 6: n = binary ? 32 : 0; break;
    case 7: n = binary ? 64 : 0; break;
    case 8: n = binary ? 128 : 0; break;
    case 9: n = binary ? 256 : 0; break;
    case 10: n = binary ? 512 : 0; break;
  }
  return n;
}

index.html

<!DOCTYPE html>
<html>
<body>
    <h2 style="text-align: center">Binary to Decimal conversion</h2>
    <div style="text-align: center">
        <form>
            <div id="decimal">0</div><br>
            <input type="text" id="binary" style="width:300px;padding:10px;font-size:16px;font-weight: 500;">
            <div style="font-size:10px;color:red" id="error"></div>
        </form>
    </div>
    <script src="./app.js"></script>
</body>
</html>

Note : It will work only one time for again reload the page

Write the program to show the tringle ?

Amit Prajapati — Thu, 14 Jul 2022 16:21:43 +0000

let space = '';
let n = '';
let m = '';
for(let i=1;i<=6;i++){
    for(let j=6;j>=i;j--){
      space = space + ' - ';
    }
    for(let z=1;z<=i;z++){
        n = n + ` ${z} `
    }
    for(let k=i-1;k>=1;k--){
        m = m + ` ${k} `
    }
    console.log(space+n+m)
    n = '';
    space = '';
    m = '';
}

Write a program to print prime numbers from 1 to 50

Amit Prajapati — Mon, 11 Jul 2022 16:19:55 +0000

for(let i=2;i<=50;i++){  
    for(let j=2;j<=i;j++){
        let reminder = i%j;
        if(i != j){
         if(!reminder) break;
        }        
        if(j==i){
          console.log( i, ' is prime number')     
        }     
    }
}

Write the code to print the odd numbers ?

Amit Prajapati — Sun, 10 Jul 2022 14:09:37 +0000

for(let i=1;i<=15;i++){
    if(i%2){
        console.log(i,'is the odd number`)
    }
}

Write the code to print the even numbers ?

Amit Prajapati — Sun, 10 Jul 2022 08:26:43 +0000

for(let i=1;i<=50;i++){
    //Divided by 2 
    if(!(i%2)){
         console.log(i,'is the event number')
    }
}

Hello World in Javascript !

Amit Prajapati — Sat, 09 Jul 2022 15:16:01 +0000

console.log(" Hello world ! ")