https://github.com/letitbasecret/es6-10_try
practicing Es6-10 for 5 times
https://github.com/letitbasecret/es6-10_try
Last synced: 4 months ago
JSON representation
practicing Es6-10 for 5 times
- Host: GitHub
- URL: https://github.com/letitbasecret/es6-10_try
- Owner: letitbasecret
- Created: 2024-06-14T20:27:29.000Z (about 2 years ago)
- Default Branch: main
- Last Pushed: 2024-06-24T13:11:12.000Z (almost 2 years ago)
- Last Synced: 2025-07-23T13:30:55.396Z (11 months ago)
- Language: HTML
- Size: 8.79 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
README
Table of Content
- Define variables (const & let)
- Template strings
- string.padStart() / string.padEnd()
- Arrow function
- Spread Operator
- Rest Operator
- Default Parameter
- Arry Destruction
- New Userful Array Method
- object destructing
- Object Enhancrment
- New Object method
- for ...of loop
- class
- import/export
- hash map
- set
- handaling error(try/catch/throw/finally)
- promisses
- async/await
console.log("hello world");
const variableName = "name";
const variableName = "name2"; //syntax error
variableName = "name3"; //syntax error
const arr = ["a", "b", "c"];
const arr = ["d", "e", "f"]; //syntax error
arr = ["g", "h", "i"]; //syntax error
//but
arr.push("k");
const obj = {
name: "name",
age: 20,
gender: "male",
};
const obj = {
name: "name2",
age: 20,
gender: "male",
}; //syntax error
//but
obj.name = "name3";
obj.age = 21;
obj.gender = "female";
obj.hobby = "football";
var x = 1; {
const x = 2;
}
console.log(x); //1
//let
let varName = "a";
let varName = "b"; //syntax error
//but
varName = "c";
var x = 1; {
let x = 2;
}
console.log(x);
//hosting var vs let
console.log(sayHello); //undefine
var sayHello = "hello world";
console.log(sayHello);
console.log(sayHello); //refrence error not defined
let sayHello = "helllo";
console.log(sayHello);
for (var i = 0; i < 3; i++) {
console.log(i);
setTimeout(function() {
console.log(i);
}, 2000);
}
console.log(i); //2
for (let i = 0; i > 3; i++) {
console.log(i);
setTimeout(function() {
console.log(i);
}, 2000);
}
console.log(i); //012
//template strings
let firstNmae = "priyanka";
let lastName = "singh";
console.log(`my name is ${firstName} ${lastName}`);
let num1 = 1;
let num2 = 2;
console.log(`sum of ${num1} and ${num2} is ${num1 + num2}`);
console.log(`line
seprate
possible
without
\n`);
let channleName = "priyankaSingh";
let baseUrl = "https:www.youtube.com/";
let url = `${baseUrl}channel/${channleName}/`;
//.padStart()
let maxLength = 15;
let name = "priyanka";
console.log(name.padStart(maxLength, "-")); //-------priyanka
console.log(name.padEnd(maxLength, "-")); //priyanka-------
//arrow function
let functionName = (par1, par2) => par1 + par2;
let fun2 = () => "hellooo world";
//callback
let arr = [1, 2, 3];
let arrFilter = (arr) =>
arr.map((value) => value * 2).filter((value) => value % 3 == 0);
arrFilter(arr);
//spread operator
let arr1 = [1, 2, 3];
let arr2 = [4, 5, 6, ...arr1, 7, 8, 9];
console.log(arr2);
//for funvtion as parameters
function fun(a, b, c) {
console.log(arguments);
return a + b + c;
}
let num = [1, 2, 3];
fun(...num);
fun(5, 6, ...num);
let num - [1, 2, 3];
Math.min(num); //NaN
Math.min(...num); //1
//rest operator
function fun(a, b, ...arrgs) {
console.log(a);
console.log(b);
console.log(arrgs);
console.log(...arrgs);
}
fun(1, 2, 3, 4, 5, 6, 7, 8, 9, 0);
//1
//2
//[3,4,5,6,7,8,9,0]
// 3 4 5 6 7 8 9 0
function smallest(...arrgs) {
return `smallest number ${Math.min(...arrgs)}`;
}
smallest(1, 2, 3, 4, 5, 6, 7, 80); //1
//default parameter
functio fun(a, b = 2, c = "fsd") {
console.log(a); //typeError
console.log(b); //2
console.log(c); //fsd
}
//array destruction
let arr = [1, 2, 3, 4, 5, 6, 7];
let [a, b, c, d, e, f, g] = arr;
console.log(a); //1
console.log(b); //2
console.log(c); //3
console.log(d); //4
....
//array methods
//.includes()
let arr = [1, 2, 3, 4, 5];
console.log(arr.includes(8)); //false
arr.map((vales) => (value));
//object destruction
const obj = {
first: "priyanka ",
last: "singh",
}
let {
first,
last
} = obj;
console.log(first); //priyanka
let {
first: firstName,
last: lastName
} = obj;
console.log(firstName);
console.log(lastName);
const obj2 = {
name: "priyanka",
city: "dhanbad",
state: "jharkhand",
country: "india",
}
let {
state,
...withoutState
} = obj2;
console.log(state);
console.log(withoutState);
function createperson({
person = {
name: "priyanka",
city: "dhanbad",
state: "jharkhand",
}
isFun = 0;
} = {}) {
return [person.name, person.state, person.city];
}
createperson();
createperson({
isFun: 1
});
createperson({
isFun: 1,
person: {
name: "priyanka",
city: "dhanbad",
state: "jharkhand"
}
});
//methods -assign() , entries() ,formEntries()
//assign()
const obj = {
name: "priyanka",
city: "dhanbad",
state: "jharkhand"
};
const obj2 = object.assign({}, obj);
obj2.name = "someting else";
console.log(obj.name); //priyanka
//entries()-----obj - array
const obj = {
name: "priyanka",
city: "dhanbad",
state: "jharkhand",
};
const arr = object.entries(obj);
connsole.log(arr);
//[["name","priyanka"],["city","dhanbad"],["state","jharkhand"]]
//formEntries()
const arr = ['a' => 1, 'b' => 2];
const obj = object.formEntries(arr);
console.log(obj);
let someValue = "firstName";
let persone = {
[someValue]: "priyanka",
};
console.log(persone);
let myobj = {
sayhello() {
console.log("hellllo");
}
};
//for ...of loop'
//itrate
const arr = [1, 2, 3, 4, 5];
for (let num of arr) {
console.log(num);
}
const st = "priyana singh";
for (let ch of st) {
console.log(ch);
}
//update
const tempArr = [];
for (let arr of tempArr) {
arr += 1;
tempArr.push(arr);
}
arr2 = tempArr;
console.log(arr2);
//class
class Person {
constructor(name, age, gender) {
this.name = name;
this.age = age;
this.gender = gender;
}
sayHello() {
return `hi! I'm ${this.name} ,${this.year }old ' ${gender}`;
}
static callStatic
};
let newPerson = new Person("priyanka ", 23, "F");
console.log(newPerson.sayHello());
//inheritance
class PersonEdu extends Person {
constructor(name, age, gender, education) {
super(name, age, gender);
this.education = education;
}
};
let newPerson = new PersonEdu("priy", 25, "F", "RSVM");
newPerson.education;
newPerson.start();
//import/export
//file1.js
export sayHello = "hello world";
export say = "hi";
//file2.js
import {
sayHello
} from "./file1.js";
import {
sayHi
} from "./file1.js";
//or
import {
sayHello as Hello
} from "./file.js";
import {
sayHi as Hi
} from "./file1.js";
//or
import * from "./file1.js";
//default
//file1.js
export default sayHello = "hello world";
//file2.js
import sayHello from "./file1.js";
//class export
class Vehical {
constructor(make, model, year) {
this.make = make;
this.model = model;
this.year = year;
}
start() {
return ` ${this.make} ${this.model} ENGINE START`;
}
}
export default Vehical;
//car.js
import Vehical from "./vehical.js";
class car extends Vehical {
constructor(make, model, year, numWheel) {
super(make, model, year);
this.numWheel = 4;
}
}
let newCar = new Car("honda", "civil", 2019);
newCar.numWheel;
newCar.start();
//Hash map
let myMap = new Map;
myMap.set(1, "something");
myMap.set(false, "something");
myMap.set([1, 2, 3], "something");
myMap.set({
1: "abc",
"something"
});
myMap.delete(false);
myMap.has(1);
myMap.size;
myMap.get(1);
myMap.clear();
.keys();
.values();
for (let [key, value] of myMap) {
console.log(key + '=' + value);
};
for (let key of myMap.key()) {
console.log(key);
};
for (let value of myMap.values) {
console.log(values);
};
//set
const mySet = new Set([1, 2, 2, 4, 4, 6]); //{1,2,4,6}
mySet.add(5);
mySet.has(3);
mySet.size();
mySet.delete();
//generator
function* genValues() {
yield "first";
yield "second";
yield "third";
};
let myGer = genValues();
myGer.next();
myGer.next().value
myGer.next().done
myGer.next()
//handalimg error(try , catch , throw , finally)
try {
undefinedFunction();
} catch (err) {
console.log("the error is" + err); //refrenceError
}
//errors- EvalError , RangeError , RefenceError , SyntaxError , TypeError ,URLError
try {
throw new ReferenceError("this is customizes error ");
} catch (err) {
if (err instanceof ReferenceError) {
console.log(this code is run when their is ReferenceError);
} else {
console.log("this code is run when some other error");
}
} finally {
console.log("this code is run no matter what");
}
//promise
const homeWork = new Promise(
function(resolve, reject) {
let isDone = false;
if (isDone) {
setTimeout(function() {
resolve("is done");
}, 2000)
} else {
setTimeout(function() {
reject(is not done);
}, 1000)
}
}
);
homeWork.then(
function(result) {
console.log(result);
}
).catch(function(result) {
console.log(result);
})
//promise chain
// async /await
async function myFun() {
return "this is a promise";
}
myFun().then((val) => {
console.log(val)
});
async function myFun() {
isDone = false;
if (isDone) {
return ("is done");
} else {
throw "is not done";
}
}
myFun().then((val) => {
console.log(val)
}).catch((val)) => {
console.log(val)
};
//await
async myFun() {
let myPromise = new Promise((resolve, reject) => {
setTimeout(() => {
resolve(done), 2000
});
});
let result = await myPromise;
return result;
}
myFun().then((val) => {
console.log(val)
}).catch((val)) => {
console.log(val)
};