Create undefined-to-null.ts

Author: kamyu104

TypeScript/undefined-to-null.ts

@@ -0,0 +1,14 @@
+// Time:  O(n)
+// Space: O(h)
+
+// dfs
+function undefinedToNull(obj: Record<any, any>): Record<any, any> {
+    Object.keys(obj).forEach(key => {
+        if (typeof obj[key] === 'object' && obj[key] !== null) {
+            obj[key] = undefinedToNull(obj[key]);
+        } else {
+            obj[key] = obj[key] ?? null;
+        }
+    });
+    return obj;
+};