String immutability

Question

Hi
I am confused when they say that string is immutable and we need to use StringBuffer instead....
But why the piece of code below is compiling if string be immutable ?
public class Main {
     * @param args the command line arguments
    public static void main(String[] args) {
String  mystring ="Hello how are you ";
mystring ="Are you fine ";
System.out.println(mystring);
}

Answer 1

nogoodatcoding wrote:
Second, Strings are immutable because once created, you cannot modify their content. That's fixed.Except...
import java.lang.reflect.*;
public class ImmutableStringDemo {
    public static void main(String[] args) throws Exception {
        String string = "foo";
        assert "foo".equals(string);
        new StringChanger().change(string);
        assert "bar".equals(string);
class StringChanger {
    public void change(String s) throws IllegalAccessException {
        Field[] fields = s.getClass().getDeclaredFields();
        for (Field f : fields) {
            f.setAccessible(true);
            if (f.getType() == char[].class) {
                f.set(s, "bar".toCharArray());
}Don't try this at home, all standard caveats apply.
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