aaa[] x=new aaa[3];
aaa[] y={new aaa(),new aaa(),new aaa()};
//其实就是这样:
//aaa[] y = new aaa[3];
//y[0] = new aaa();y[1] = new aaa();y[2] = new aaa();
aaa[] y={new aaa(),new aaa(),new aaa()};
//其实就是这样:
//aaa[] y = new aaa[3];
//y[0] = new aaa();y[1] = new aaa();y[2] = new aaa();
对象则自动为nullprintln时调用String.valueOf(),
null -> "null"
object -> object.toString();aaa extends Object and didn't change Object.toString(){
return getClass().getName()+"@"+hashCode();
}