Random Tips

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for of usage 

				
					//2.for of usage
let productDetails = [
  {
    product_Id: 1,
    product_Name: "LG Monitor",
    price: "55k",
    rating: "super",
  },
  {
    product_Id: 2,
    product_Name: "LG Curve Monitor",
    price: "45k",
    rating: "Average",
  },
];

for (let obj of productDetails) {
  console.log(JSON.stringify(obj));
}

/*
Basically used to send data to backend server
{"product_Id":1,"product_Name":"LG Monitor","price":"55k","rating":"super"}
{"product_Id":2,"product_Name":"LG Curve Monitor","price":"45k","rating":"Average"}
*/

JSON.PARSE USAGE IN LOCAL STORAGE

				
					let employee = {
  name: "Anurag",
  code: "empCode-123",
};

const obj = JSON.stringify(employee);
console.log(obj); //{"name":"Anurag","code":"empCode-123"} -->in string

localStorage.setItem("key", obj);

//WRONG KEY
console.log(JSON.parse(localStorage.getItem("key1"))); //null
//CORRECT KEY 
console.log(JSON.parse(localStorage.getItem("key"))); //{name: 'Anurag', code: 'empCode-123'}
//CORRECT KEY WITOUT PARSE
console.log(localStorage.getItem("key")); //{name: 'Anurag', code: 'empCode-123'} -->in string...

Change the background color

				
					 //HTML part
 <button id="blue">blue</button>
 <button id="green">green</button>
 <button id="yellow">yellow</button>
    
    
//Javascript part    
const changeColor = (color) => {
  document.body.style.background = color;
};

document.querySelector("#blue").addEventListener("click", () => changeColor("blue"));
document.querySelector("#green").addEventListener("click", () => changeColor("green"));
document.querySelector("#yellow").addEventListener("click", () => changeColor("yellow"));

Password Validity Question

				
					function checkPassword(password) {
  let onelowercaseLetter = /(?=.+[a-z])/;
  let oneUppercaseLetter = /(?=.+[A-Z])/;
  let oneDigit = /(?=.+[0-9])/;
  let oneSpecialCharacter = /(?=.+[!@#$%^&*])/;
  let minEightDigit = /(?=.{8,})/;
  let isValid =
    onelowercaseLetter.test(password) &&
    oneUppercaseLetter.test(password) &&
    oneDigit.test(password) &&
    oneSpecialCharacter.test(password) &&
    minEightDigit.test(password);

  return isValid ? "passoword is valid" : "password is invalid";
}

console.log(checkPassword("aZ#1333ddd3"));
console.log(checkPassword("anurag"));

JSON.stringify certain properties

				
					const address = { city: "Rayagada", state: "Odisha" };
const employee = { name: "Anurag", gender: "Male", ...address };
console.log(employee); //{name: 'Anurag', gender: 'Male', city: 'Rayagada', state: 'Odisha'}

//{"name":"Anurag","gender":"Male","state":"Odisha"}
//it only strigified --> name , gender , state
console.log(JSON.stringify(employee, ["name", "gender", "state"]));

Deep cloning

				
					//********** Deep cloning  **************


var cricketer = {
  name: "Virat",
  team: "India",
  age: 32,
  colleagues: {
    name: "Rohit",
  },
  performance: function (type) {
    return `${this.name} is ${type} player`;
  },
};
var copyCricketer = cricketer;
copyCricketer.age = 42;

console.log(copyCricketer);

console.log(cricketer);



				
			
				
					var copyCricketer1 = JSON.parse(JSON.stringify(cricketer));
copyCricketer1.age = 45;
console.log(copyCricketer1);
console.log(cricketer);
				
			
				
					var copyCricketer2 = Object.assign({}, cricketer);
copyCricketer2.colleagues.name = "Rahane";
copyCricketer2.age = 34;
console.log(copyCricketer2);
console.log(cricketer);
				
			
				
					let spreadCricketerCopy = { ...cricketer };
spreadCricketerCopy.colleagues.name = "Rahane";
spreadCricketerCopy.age = 34;
console.log(spreadCricketerCopy);
console.log(cricketer);
				
			
				
					let finalDeepCopy = _.cloneDeep(cricketer);
finalDeepCopy.colleagues.name = "Rahane";
console.log(finalDeepCopy);
console.log(cricketer);

Generate Random number

				
					//Generate Random Number
Math.random(); //gives you decimal between 0 and 1

//I want to generate random number between 1 and 100
Math.ceil(Math.random()) * 100;

//I want to generate random number between 1 and 10
Math.ceil(Math.random()) * 10;

//I want to generate random number between 20 and 30
Math.ceil(Math.random()) * 10 + 20;

//I want to generate random number between 20 and 50
Math.ceil(Math.random() * (50 - 20)) + 20;

create a private variable in Javascript

				
					const accessPrivateKey = () => {
  let privateKey = "Private Key";
  return function () {
    return privateKey;
  };
};

let getPrivateKey = accessPrivateKey();
console.log(getPrivateKey()); //Private Key

console.log(accessPrivateKey());
//
// ƒ () {
//   return privateKey;
// }

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