Add hash table implementation

Author: kamranahmedse

hashtable.js

@@ -0,0 +1,93 @@
+class Node {
+	constructor(key, value) {
+		this.key = key;
+		this.value = value;
+		this.next = null;
+	}
+}
+
+class Table {
+	constructor(size) {
+		this.cells = new Array(size);
+	}
+
+	hash(key) {
+		let total = 0;
+
+		for (let i = 0; i < key.length; i++) { 
+      total += key.charCodeAt(i);
+    }
+
+		return total % this.cells.length;
+	}
+
+	insert(key, value) {
+		const hash = this.hash(key);
+
+		if (!this.cells[hash]) {
+			this.cells[hash] = new Node(key, value);
+		} else if (this.cells[hash].key === key) {
+			this.cells[hash].value = value;
+		} else {
+			let node = this.cells[hash];
+
+			while (node.next) {
+				if (node.next.key === key) {
+					node.next.value = value;
+					return;
+				}
+
+				node = node.next;
+			}
+
+			node.next = new Node(key, value);
+		}
+	}
+
+	get(key) {
+		const hash = this.hash(key);
+		if (!this.cells[hash]) {
+      return null; 
+    }
+
+    let node = this.cells[hash];
+
+    while (node) {
+      if (node.key === key) {
+        return node.value;
+      }
+
+      node = node.next;
+    }
+
+    return null;
+	}
+
+	getAll() {
+		const table = [];
+
+		for (let i = 0; i < this.cells.length; i++) {
+			const cell = [];
+			let node = this.cells[i];
+
+			while (node) {
+				cell.push(node.value);
+				node = node.next;
+			}
+
+			table.push(cell);
+		}
+
+		return table;
+	}
+}
+
+const table = new Table(5);
+table.insert("baa", 1);
+table.insert("aba", 2);
+table.insert("aba", 3);
+table.insert("aac", 4);
+table.insert("aac", 5);
+
+console.log(table.get('aac'));
+console.log(table.get('baa'));