Problem
Given an object or an array, return if it is empty.
- An empty object contains no key-value pairs.
- An empty array contains no elements.
You may assume the object or array is the output of JSON.parse.
Example 1:
Input: obj = {"x": 5, "y": 42}
Output: false
Explanation: The object has 2 key-value pairs so it is not empty.
Example 2:
Input: obj = {}
Output: true
Explanation: The object doesn't have any key-value pairs so it is empty.
Example 3:
Input: obj = [null, false, 0]
Output: false
Explanation: The array has 3 elements so it is not empty.
Constraints:
2 <= JSON.stringify(obj).length <= 105
Can you solve it in O(1) time?
Solution (Javascript)
/**
* @param {Object | Array} obj
* @return {boolean}
*/
var isEmpty = function (obj) {
for (const _ in obj) return false;
return true;
};
Explain:
nope.
Complexity:
- Time complexity : O(n).
- Space complexity : O(n).