Implement lodash.get(obj, path, defaultValue)

Question

Accepted Answer

**Approach:** Normalize path to keys array (split by `.` and `[]`), then reduce, returning defaultValue if `null/undefined` encountered.

```javascript
function get(obj, path, defaultValue) {
  const keys = Array.isArray(path) ? path : path.replace(/$$(\w+)$$/g, '.$1').split('.').filter(Boolean);
  let cur = obj;
  for (const k of keys) {
    if (cur == null) return defaultValue;
    cur = cur[k];
  }
  return cur === undefined ? defaultValue : cur;
}

// Demo
const obj = { a: { b: [{ c: 3 }], 'd.e': 5 } };
console.log(get(obj, 'a.b[0].c')); // 3
console.log(get(obj, 'a.b[0].x', 'default')); // default
console.log(get(obj, ['a','b',0,'c'])); // 3
console.log(get(obj, 'a.missing.c', 42)); // 42
console.log(get(null, 'a.b', 'fallback')); // fallback
console.log(get(obj, 'a.b[1].c', null)); // null
```
Handles `a[0].b` via regex `$$(\w+)$$` → `.\$1`.

Implement lodash.get(obj, path, defaultValue)

Understand the problem

Attempt it yourself

Study the solution

Solution ready — 2 min read

Join the discussion

Discussion (0)

KEEP THE
STREAK ALIVE.

Understand the problem

Attempt it yourself

Study the solution

Solution ready — 2 min read

Join the discussion

Discussion (0)

KEEP THESTREAK ALIVE.

KEEP THE
STREAK ALIVE.