1class ExpiringCache {
2    constructor(defaultTTL = 3600000) {  // 1 hour in milliseconds
3        this.cache = new Map();
4        this.timeouts = new Map();
5        this.defaultTTL = defaultTTL;
6    }
7
8    set(key, value, ttl = this.defaultTTL) {
9        const expiryTime = Date.now() + ttl;
10        
11        if (this.timeouts.has(key)) {
12            clearTimeout(this.timeouts.get(key));
13        }
14
15        const timeoutId = setTimeout(() => {
16            this.delete(key);
17        }, ttl);
18
19        this.cache.set(key, {
20            value,
21            expiryTime
22        });
23        this.timeouts.set(key, timeoutId);
24
25        return this;
26    }
27
28    get(key) {
29        const item = this.cache.get(key);
30        if (!item) return undefined;
31
32        if (Date.now() > item.expiryTime) {
33            this.delete(key);
34            return undefined;
35        }
36
37        return item.value;
38    }
39
40    delete(key) {
41        clearTimeout(this.timeouts.get(key));
42        this.timeouts.delete(key);
43        this.cache.delete(key);
44    }
45}
46
47const cache = new ExpiringCache(2000);  // 2 seconds TTL
48cache.set('product1', { name: 'Laptop', price: 999 });
49cache.set('product2', { name: 'Phone', price: 699 }, 1000);  // 1 second TTL
50
51setTimeout(() => {
52    console.log('After 1.5 seconds:');
53    console.log('Product1:', cache.get('product1'));
54    console.log('Product2:', cache.get('product2'));
55}, 1500);