firstHalf
Given a string, return the first half of the string. If the string length is odd, return the first half rounded down.
Examples
firstHalf('Hello') → 'He'
firstHalf('abcdef') → 'abc'
firstHalf('ab') → 'a'
Starter code
function firstHalf(str) {
}
Complexity of the optimal solution
Time O(n), space O(n). The `substring` method creates a new string. In the worst case, this new string can be up to half the length of the original string (n). Creating this new string takes O(n) time and O(n) space.