why is the top codes wrong??

[lwz123]

1.public Clock (Clock existingClock)
{
hours = existingClock.hours;
isTicking = existingClock.isTicking;
}

2.public Clock (Clock newClock)
{
hours = newClock.hours;
isTicking = newClock.isTicking;
}

[Fubarable]

The two constructors are completely indistinguishable. Why do you think that one is "wrong"?

[Kagiso]

Please be warned that I may be wrong as I am new to Java

what you have written looks like two constructor methods which take the same arguments(of type Clock)... For method overloading this can't be done.
have you declared the variables (hours & isTicking)?

perhaps you were trying to say
hours = existingClock.hours();
isTicking = existingClock.isTicking(); // which also doesn't make sense

[Junky]

two constructor methods

There are constructors and there are methods. No such thing as a constructor method.