Recover the TS code.

codes/typescript/module/ListNode.ts

@@ -0,0 +1,9 @@
+// Definition for singly-linked list.
+export default class ListNode {
+    val: number;
+    next: ListNode | null;
+    constructor(val?: number, next?: ListNode | null) {
+        this.val = val === undefined ? 0 : val;
+        this.next = next === undefined ? null : next;
+    }
+}

codes/typescript/module/PrintUtil.ts

@@ -0,0 +1,18 @@
+/*
+ * File: PrintUtil.ts
+ * Created Time: 2022-12-10
+ * Author: Justin (xiefahit@gmail.com)
+ */
+
+import ListNode from './ListNode';
+
+function printLinkedList(head: ListNode | null): void {
+    const list: string[] = [];
+    while (head !== null) {
+        list.push(head.val.toString());
+        head = head.next;
+    }
+    console.log(list.join(' -> '));
+}
+
+export { printLinkedList };