localstorage

1// localStorage for objects, arrays or any data type
2var obj = {
3	firstName: "Bob",
4    lastName: "Jeff",
5    age: 13
6}
7localStorage.setItem("itemname", JSON.stringify(obj)); // Save the obj as string
8var item = JSON.parse(localStorage.getItem("itemname")); 
9// ^^ Parse string then set `item` as the obj

1window.localStorage.setItem('myCat', 'Tom');
2const cat = window.localStorage.getItem('myCat');

1localStorage.setItem('name', 'Bob') // make/set a key/value
2var username = localStorage.getItem('name') // get the key
3console.log(username) // log the key
4// This data will be saved even after you close the page

1localStorage.setItem('Items' , 'Bread');
2let Bread = localStorage.getItem('Items');

1// using in HTML5 (frontend)
2
3// set
4localStorage.setItem('users', 'vilh'); 
5
6users = [
7	{
8    	id: 1,
9        name: 'vilh',
10    },
11    {
12    	id: 2,
13        name: 'zidane'
14    },
15]
16
17// set string 
18localStorage.setItem('users', users);	// stored objects
19localStorage.setItem('users', JSON.stringify(users));	// stored string
20
21// get
22var retrievedUsername = localStorage.getItem('users'); 

1    import { Injectable, OnDestroy } from '@angular/core';
2    import { Subject } from 'rxjs/Subject';
3    import { share } from 'rxjs/operators';
4    
5    @Injectable()
6    export class StorageService implements OnDestroy {
7      private onSubject = new Subject<{ key: string, value: any }>();
8      public changes = this.onSubject.asObservable().pipe(share());
9    
10      constructor() {
11        this.start();
12      }
13    
14      ngOnDestroy() {
15        this.stop();
16      }
17    
18      public getStorage() {
19        let s = [];
20        for (let i = 0; i < localStorage.length; i++) {
21          s.push({
22            key: localStorage.key(i),
23            value: JSON.parse(localStorage.getItem(localStorage.key(i)))
24          });
25        }
26        return s;
27      }
28    
29      public store(key: string, data: any): void {
30        localStorage.setItem(key, JSON.stringify(data));
31        this.onSubject.next({ key: key, value: data})
32      }
33    
34      public clear(key) {
35        localStorage.removeItem(key);
36        this.onSubject.next({ key: key, value: null });
37      }
38    
39    
40      private start(): void {
41        window.addEventListener("storage", this.storageEventListener.bind(this));
42      }
43    
44      private storageEventListener(event: StorageEvent) {
45        if (event.storageArea == localStorage) {
46          let v;
47          try { v = JSON.parse(event.newValue); }
48          catch (e) { v = event.newValue; }
49          this.onSubject.next({ key: event.key, value: v });
50        }
51      }
52    
53      private stop(): void {
54        window.removeEventListener("storage", this.storageEventListener.bind(this));
55        this.onSubject.complete();
56      }
57    }
58

1var cat = localStorage.getItem('myCat');

1localStorage.removeItem('myCat');