Arrays and final qualifier

One has to be careful regarding arrays which are declared final. It only means that the whole array reference itself cannot be changed to point to a different array. Individual elements of the array can be modified. I have an example below to depict this:

public class TestFinalArray {

    final StringBuilder[] array;
    
    TestFinalArray(int size, String... records) {
        //Initialize final array
        array = new StringBuilder[size];
        for (int i = 0; i < size; i++) {
            array[i] = new StringBuilder(records[i]);
        }
        
    }
    
    public static void main(String[] args) {
        TestFinalArray tfa = 
            new TestFinalArray(3, new String[] {"1","2", "3"});
        print("Original array", tfa.array);
        //Modify elements of the array
        tfa.array[0] = new StringBuilder("Hello");
        tfa.array[1] = tfa.array[1].append("World");
        print("After Modification", tfa.array);

    }
    
    public static void print(String s, StringBuilder[] array) {
        if (s != null) {
            System.out.println(s);
        }
        for (StringBuilder elem: array) {
            System.out.println(elem);
        }
    }
    
}

Output:
Original array
1
2
3
After Modification
Hello
2World
3