Example 1:
Input: nums = [2,7,11,15], target = 9 Output: [0,1] Explanation: Because nums[0] + nums[1] == 9, we return [0, 1].
const twoSum = function(nums, target) {
const map = {}
for (let i=0; i<nums.length;i++) {
if (map[target-nums[i]] !==undefined ) return [map[target-nums[i]],i]
else map[nums[i]] = i
}
}
Now my question is...
if (map[target-nums[i]] !==undefined ) return [map[target-nums[i]],i]
From the code above, when i first coded this, i wrote:
if (map[target-nums[i]]) return [map[target-nums[i]],i]. (without !==undefined)
Thinking that if i have the pair in the hashmap, it would work, but it did not work, and when i looked up the answer, i realized i had to write !==undefined. Why are these considered different?
