Why is the position of the or-argument relevant?

Hello, I wrote a program in C++ that reads words from the command line and then outputs them from shortest to longest. The program works. However, there's a problem I don't understand. In the "next" function of the "array" class, swapping the if conditions (result == nullptr) and (y[i] < *result) displays a different result: only the shortest word. Why is this?

 #include <iostream> #include <cstdlib> #include <string> using namespace std; template <typename T, typename K> class Paar { private:    T ersten;    K zweiten; public:    Paar() {}    Paar(T a, K b) : ersten(a), zweiten(b) {}    T getErsten() const { return ersten; }    K getZweiten() const { return zweiten; }    bool operator ==(const Paar& a) const{        return (ersten == a.ersten);    }    bool operator <(const Paar& b) const{        return (ersten < b.ersten);    } }; template <typename T1> class Array { private:    T1* y;    int size;    int occupied; public:    Array(int x) : y(new T1[x]), size(x), occupied(0) {}    bool dazu(const T1& x) {        if (occupied < size) {            y[occupied] = x;            occupied++;            return true;        }        return false;    }    T1* keinste() {        int j = 0;        if (occupied == 0) {            return nullptr;        }        for (int i = 1; i < occupied; i++) {            if (y[i] < y[j]) {                j = i;            }        }        return &y[j];    }    T1* naechstes(const T1& a) {        T1 * ergebnis = nullptr;        if (occupied == 0) {            return nullptr;        }        for (int i = 0; i < size; i++) {            if ((a < y[i]) && ((ergebnis == nullptr) || (y[i] < *ergebnis))) {                ergebnis = &y[i];            }        }       /* if ((*ergebnis < a) || (*ergebnis == a)) {            return nullptr;        } */        return ergebnis;    }    ~Array() { delete[] y; } }; int main(int argc, const char* argv[]) {    typedef Paar<string, int> PaarType;    Array<PaarType> a(argc - 1);    for (int i = 1; i < argc; i++) {        PaarType b(argv[i], i);        a.dazu(b);    }    for (PaarType* c = a.keinste(); c != nullptr; c = a.naechstes(*c)) {        cout << "erster Wert: " << c->getErsten() << " zweiter Wert: " << c->getZweiten() << endl;    }    return 0; }