Test Case: java-instruct-991

```java
import java.util.Arrays;
import java.util.function.Function;

class Solution {

    /**
     * Transforms an array of primitive data type to another array of a different primitive data type
     * by applying a given function to each element.
     *
     * @param inputArray The input array of primitive data type. Can be null.
     * @param transform  The function to apply to each element of the input array.
     * @param <T>        The type of the input array elements (e.g., Integer, Double, Float).
     * @param <R>        The type of the output array elements (e.g., Long, String, Boolean).
     * @return An array of the same size as the input array, containing the results of calling the
     * specified method on each element of the input array. Returns an empty array if the input
     * array is null or has zero length.
     */
    public static <T, R> R[] transformArray(T[] inputArray, Function<T, R> transform, R[] outputArrayType) {
        if (inputArray == null || inputArray.length == 0) {
            return Arrays.copyOf(outputArrayType, 0); // Return an empty array of the correct type
        }

        R[] resultArray = Arrays.copyOf(outputArrayType, inputArray.length);

        for (int i = 0; i < inputArray.length; i++) {
            resultArray[i] = transform.apply(inputArray[i]);
        }

        return resultArray;
    }

    public static void main(String[] args) {
        // Example usage:
        Integer[] intArray = {1, 2, 3, 4, 5};
        Long[] longArray = transformArray(intArray, Integer::longValue, new Long[0]);
        System.out.println(Arrays.toString(longArray)); // Output: [1, 2, 3, 4, 5]

        Double[] doubleArray = {1.1, 2.2, 3.3};
        String[] stringArray = transformArray(doubleArray, Object::toString, new String[0]);
        System.out.println(Arrays.toString(stringArray)); // Output: [1.1, 2.2, 3.3]

        Float[] floatArray = {1.0f, 2.0f, 3.0f};
        Integer[] integerArray = transformArray(floatArray, Float::intValue, new Integer[0]);
        System.out.println(Arrays.toString(integerArray)); // Output: [1, 2, 3]

        Integer[] nullArray = null;
        Long[] emptyLongArray = transformArray(nullArray, Integer::longValue, new Long[0]);
        System.out.println(Arrays.toString(emptyLongArray)); // Output: []

        Integer[] emptyArray = {};
        Long[] anotherEmptyLongArray = transformArray(emptyArray, Integer::longValue, new Long[0]);
        System.out.println(Arrays.toString(anotherEmptyLongArray)); // Output: []
    }
}
```
```python
import numpy as np

def transform_array(input_array, transform, dtype):
    """
    Transforms an array of primitive data type to another array of a different primitive data type
    by applying a given function to each element.

    Args:
        input_array (numpy.ndarray): The input array of primitive data type. Can be None.
        transform (callable): The function to apply to each element of the input array.
        dtype (type): The data type of the output array.

    Returns:
        numpy.ndarray: An array of the same size as the input array, containing the results of calling the
                       specified method on each element of the input array. Returns an empty array if the input
                       array is None or has zero length.
    """
    if input_array is None or len(input_array) == 0:
        return np.array([], dtype=dtype)

    result_array = np.array([transform(x) for x in input_array], dtype=dtype)
    return result_array

if __name__ == '__main__':
    # Example usage:
    int_array = np.array([1, 2, 3, 4, 5])
    long_array = transform_array(int_array, lambda x: np.int64(x), np.int64)
    print(long_array)  # Output: [1 2 3 4 5]

    double_array = np.array([1.1, 2.2, 3.3])
    string_array = transform_array(double_array, str, str)
    print(string_array)  # Output: ['1.1', '2.2', '3.3']

    float_array = np.array([1.0, 2.0, 3.0], dtype=np.float32)
    int_array2 = transform_array(float_array, int, int)
    print(int_array2)  # Output: [1 2 3]

    null_array = None
    empty_long_array = transform_array(null_array, lambda x: np.int64(x), np.int64)
    print(empty_long_array)  # Output: []

    empty_array = np.array([])
    another_empty_long_array = transform_array(empty_array, lambda x: np.int64(x), np.int64)
    print(another_empty_long_array)  # Output: []
```
```cpp
#include <iostream>
#include <vector>
#include <algorithm>

template <typename T, typename R>
std::vector<R> transformArray(const std::vector<T>& inputArray, R (*transform)(T)) {
    if (inputArray.empty()) {
        return std::vector<R>(); // Return an empty vector
    }

    std::vector<R> resultArray(inputArray.size());
    std::transform(inputArray.begin(), inputArray.end(), resultArray.begin(), transform);

    return resultArray;
}

// Example transform functions
double intToDouble(int x) {
    return static_cast<double>(x);
}

std::string doubleToString(double x) {
    return std::to_string(x);
}

int floatToInt(float x) {
    return static_cast<int>(x);
}

int main() {
    // Example usage:
    std::vector<int> intArray = {1, 2, 3, 4, 5};
    std::vector<double> doubleArray = transformArray(intArray, intToDouble);
    std::cout << "Double Array: ";
    for (double val : doubleArray) {
        std::cout << val << " ";
    }
    std::cout << std::endl; // Output: 1 2 3 4 5

    std::vector<double> doubleArray2 = {1.1, 2.2, 3.3};
    std::vector<std::string> stringArray = transformArray(doubleArray2, doubleToString);
    std::cout << "String Array: ";
    for (const std::string& val : stringArray) {
        std::cout << val << " ";
    }
    std::cout << std::endl; // Output: 1.100000 2.200000 3.300000

    std::vector<float> floatArray = {1.0f, 2.0f, 3.0f};
    std::vector<int> integerArray = transformArray(floatArray, floatToInt);
    std::cout << "Integer Array: ";
    for (int val : integerArray) {
        std::cout << val << " ";
    }
    std::cout << std::endl; // Output: 1 2 3

    std::vector<int> emptyArray;
    std::vector<double> anotherEmptyDoubleArray = transformArray(emptyArray, intToDouble);
    std::cout << "Empty Double Array Size: " << anotherEmptyDoubleArray.size() << std::endl; // Output: 0

    return 0;
}
```

```java
import java.util.Arrays;
import java.util.function.Function;

class Solution {
    /**
     * Transforms an array of one primitive type to another by applying a given function.
     *
     * @param inputArray The input array of primitive type (e.g., int, double, float).
     * @param transform  A function that takes an element of the input array and returns
     *                   an element of the output array's type.
     * @param <T>        The type of the input array elements (e.g., Integer, Double, Float).
     * @param <R>        The type of the output array elements (e.g., Integer, Double, Float).
     * @return An array of the same size as the input array, containing the results of
     *         applying the specified function to each element. Returns an empty array if
     *         the input array is null or empty.
     */
    public static <T, R> R[] transformArray(T[] inputArray, Function<T, R> transform, Class<R> outputType) {
        if (inputArray == null || inputArray.length == 0) {
            return (R[]) java.lang.reflect.Array.newInstance(outputType, 0);
        }

        R[] outputArray = (R[]) java.lang.reflect.Array.newInstance(outputType, inputArray.length);
        for (int i = 0; i < inputArray.length; i++) {
            outputArray[i] = transform.apply(inputArray[i]);
        }

        return outputArray;
    }

    public static void main(String[] args) {
        // Example usage with Integer to String conversion
        Integer[] intArray = {1, 2, 3, 4, 5};
        Function<Integer, String> intToString = Object::toString;
        String[] stringArray = transformArray(intArray, intToString, String.class);
        System.out.println(Arrays.toString(stringArray)); // Output: [1, 2, 3, 4, 5]

        // Example usage with Double to Integer conversion
        Double[] doubleArray = {1.5, 2.7, 3.9, 4.1, 5.3};
        Function<Double, Integer> doubleToInt = Double::intValue;
        Integer[] intArray2 = transformArray(doubleArray, doubleToInt, Integer.class);
        System.out.println(Arrays.toString(intArray2)); // Output: [1, 2, 3, 4, 5]

        // Example with null input
        Integer[] nullArray = null;
        String[] emptyStringArray = transformArray(nullArray, Object::toString, String.class);
        System.out.println(Arrays.toString(emptyStringArray)); // Output: []

        // Example with empty input
        Integer[] emptyArray = {};
        String[] emptyStringArray2 = transformArray(emptyArray, Object::toString, String.class);
        System.out.println(Arrays.toString(emptyStringArray2)); // Output: []
    }
}
```