Create lru.js

Algorithms/Javascript/lru.js

@@ -0,0 +1,48 @@
+class LRUCache {
+    constructor(capacity) {
+        this.capacity = capacity;
+        this.cache = new Map();
+    }
+
+    get(key) {
+        if (!this.cache.has(key)) return -1;
+
+        const value = this.cache.get(key);
+
+        this.cache.delete(key);
+        this.cache.set(key, value);
+
+        return value;
+    }
+
+    put(key, value) {
+        if (this.cache.has(key)) {
+            this.cache.delete(key);
+        }
+
+        this.cache.set(key, value);
+
+        if (this.cache.size > this.capacity) {
+            const lruKey = this.cache.keys().next().value;
+            this.cache.delete(lruKey);
+        }
+    }
+
+    display() {
+        const arr = [];
+        for (const [key, value] of this.cache.entries()) {
+            arr.push(`[key=${key} value=${value}]`);
+        }
+        console.log(`[${arr.join(', ')}]`);
+    }
+}
+
+const cache = new LRUCache(5);
+
+for (let i = 1; i <= 5; i++) {
+    cache.put(i, i * 2 + 3);
+}
+
+cache.display();
+
+console.log('Getting key 3:', cache.get(3));