Pick the oldest object from an array.

I’m making a tower defense game and i need my towers to always prioritise enemies that are the closest to the end point. Each enemy has a “age” variable. I’m trying to create an array of enemies that are currently in tower’s range. How do i make the tower pick the object with the biggest “age” variable?

Something like this should work:

int oldestIndex;

for (int i = 0; i < array.Count() - 1; i++) {
    if (array*.age > array[oldestIndex].age) {*

oldestIndex = i;

//Now attack the object at array[oldestIndex];

Sort the array old-to-new every few frames, then choose the object at the front of the array.