Can you please review my syntax?

Im not sure if I wrote my if statement correctly and I'm confused about how to construct my for loop

MyVector(size_t capacity = MyVector::DEFAULT_CAPACITY) {

capacity_ = capacity;

size_ = 0;

// make a line for if the capacity is less than MINIMUM_CAPACITY then set it to MINIMUM_CAPACITY then make an empty array with that capacity

if (capacity_ < MINIMUM_CAPACITY) {

capacity_ = MINIMUM_CAPACITY;

}

data_ = new T[capacity_];

}

MyVector(const MyVector &other)

{

capacity_ = other.capacity_;

size_ = other.size_;

data_ = new T[capacity_];

data_[i] = other.data_[i];

// make a for loop based on the other vector's size and copy the elements in the other vector's array one by one