Easy peasy First Odd Int

Easy peasy First Odd Int

In a given array, find the first integer that appears an odd number of times. Given that only one integer occurs odd number of times.

One line solution to this is by using the infamous reduce operation of Javascript.

const findOddInt = (arr) => arr.reduce((a, b) => a ^ b);

Always go for functional and tuned solution, reason it being faster ;)

For those who are wondering, ^ is the symbol for XOR. a^a = 0 and 0^a = a. So, all the numbers that occur even times will get reduced to 0 and the number that occurs odd number of times would remain.