Chapter 2 All things are objects
{
String S = New String ("a string");
} / * End of scope * /
s This REFERENCE has no trace that disappears outside the living space, but the String object that is previously referred to, still continues to take up memory.
Chapter III Control Process Process
When you assign an object, what you do is actually their REFRENCE, such as: c = D, actually pointing C and D to the object that D originally referred to.
Math.random () will produce a value between 0 and 1 (double)
Chapter 4 Initialization and Cleaning
Each overload function has a unique quotient column.
In Java, you can give this a quoter column, so that we can call other constructor directly (C can not be said) in the constructor.
Chapter 5 Hidden Realization
Chapter 6 Repeats Classes
If you do not specify access permissions for the member function, default is Friendly.
The call to the Base Class constructor must be the first thing to do by the Drivered Class constructor.
Upcasting (Upcasting)
Final Data
1. It can be "compile period constant" that never changes;
2. Can be initialized during the execution period, but you don't want to change it again.
Final When used for Reference, this Reference cannot point to other objects, but the value of the object can still be changed.
Final Methods
1. Slide this function so that Drivered Classes cannot change its meaning.
2. Efficiency.
Final Classes
Chapter VII
Method-Call is a later binding. (C is a preliminary binding)
In the inheritance relationship, if you have some special cleaning activities, you have to override Finalize (), you can remember to call the base class's femalize (), if not, the Base Class's termination action will not occur.
Performing period not identification (RTTI)
Chapter 8 Interface and Inclusion
Java's multi-inheritance (realization multiple interfaces) interfaces can also inherit multiple interfaces
The data members within Inteface will automatically become Static and Final, which can be initialized by a very square expression.
Static hidden category can write main to test the use of the Class.
Chapter 9 holds your object
Return to an Array (C / C is not available)
Arrays offers overloaded equals ()
List will be placed in an insertion order, and SET does not accept repeating elements, using one of themselves, MAP does not accept repetitive elements (judgments with KEY), using one of themselves.
