JAVASCRIPT

set in javascript

let mySet = new Set()

mySet.add(1)           // Set [ 1 ]
mySet.add(5)           // Set [ 1, 5 ]
mySet.add(5)           // Set [ 1, 5 ]
mySet.add('some text') // Set [ 1, 5, 'some text' ]
let o = {a: 1, b: 2}
mySet.add(o)

mySet.add({a: 1, b: 2})   // o is referencing a different object, so this is okay

mySet.has(1)              // true
mySet.has(3)              // false, since 3 has not been added to the set
mySet.has(5)              // true
mySet.has(Math.sqrt(25))  // true
mySet.has('Some Text'.toLowerCase()) // true
mySet.has(o)       // true

mySet.size         // 5

mySet.delete(5)    // removes 5 from the set
mySet.has(5)       // false, 5 has been removed

mySet.size         // 4, since we just removed one value

console.log(mySet)
// logs Set(4) [ 1, "some text", {…}, {…} ] in Firefox
// logs Set(4) { 1, "some text", {…}, {…} } in Chrome

set javascript

// Use to remove duplicate elements from the array 

const numbers = [2,3,4,4,2,3,3,4,4,5,5,6,6,7,5,32,3,4,5]

//spreading numbers of the object into an array using the new operator
console.log([...new Set(numbers)]) 

// [2, 3, 4, 5, 6, 7, 32]

what is new set in javascript

A set is a collection of items which are unique i.e no element can be repeated. 
Set in ES6 are ordered: elements of the set can be iterated in the insertion 
order. Set can store any types of values whether primitive or objects. 
var set4 = new Set();

js set

// Use to remove duplicate elements from the array 

const array = [2,3,4,4,2,3,3,4,4,5,5,6,6,7,5,32,3,4,5]

//spreading numbers of the object into an array using the new operator
console.log([...new Set(array)]) 

// [2, 3, 4, 5, 6, 7, 32]

javaScript new Set() Method

// Create a Set
const letters = new Set(["a","b","c"]);

...new Set() in javascript

let Arr = [1,2,2,2,3,4,4,5,6,6];

//way1
let unique = [...new Set(Arr)];
console.log(unique);

//way2
function removeDuplicate (arr){
	return arr.filter((item,index)=> arr.indexOf(item) === index);
}

removeDuplicate(Arr);

set in javascript

const mySet1 = new Set()

mySet1.add(1)           // Set [ 1 ]
mySet1.add(5)           // Set [ 1, 5 ]
mySet1.add(5)           // Set [ 1, 5 ]
mySet1.add('some text') // Set [ 1, 5, 'some text' ]
const o = {a: 1, b: 2}
mySet1.add(o)

mySet1.add({a: 1, b: 2})   // o is referencing a different object, so this is okay

mySet1.has(1)              // true
mySet1.has(3)              // false, since 3 has not been added to the set
mySet1.has(5)              // true
mySet1.has(Math.sqrt(25))  // true
mySet1.has('Some Text'.toLowerCase()) // true
mySet1.has(o)       // true

mySet1.size         // 5

mySet1.delete(5)    // removes 5 from the set
mySet1.has(5)       // false, 5 has been removed

mySet1.size         // 4, since we just removed one value

mySet1.add(5)       // Set [1, 'some text', {...}, {...}, 5] - a previously deleted item will be added as a new item, it will not retain its original position before deletion

console.log(mySet1)
// logs Set(5) [ 1, "some text", {…}, {…}, 5 ] in Firefox
// logs Set(5) { 1, "some text", {…}, {…}, 5 } in Chrome

Create JavaScript Set

// create Set
const set1 = new Set(); // an empty set
console.log(set1); // Set {}

// Set with multiple types of value
const set2 = new Set([1, 'hello', {count : true}]);
console.log(set2); // Set {1, "hello", {count: true}}

javaScript set() Method

// Create a Map
const fruits = new Map();

// Set Map Values
fruits.set("apples", 500);
fruits.set("bananas", 300);
fruits.set("oranges", 200);

js Set

const id = new Set();

id.add(1);
id.add(2);
id.add(3);
id.add(3);// duplicate value will not be added
console.log(id);// output: Set {1, 2, 3}
id.delete(2);// delete the value 2 from the set
console.log(id);// output: Set {1, 3}
id.has(2);// check if the set has the value 2 // output: true
console.log(id);


//order is not guaranteed

set method in javascript

const language = {
  set current(name) {
    this.log.push(name);
  },
  log: []
};

language.current = 'EN';
language.current = 'FA';

console.log(language.log);
// expected output: Array ["EN", "FA"]