[Repost] Some of the Java learning process see it today, the article is very easy to understand, and the beginners can learn more about the key parts described below in the process of learning. Many of the above is the author's personal point of view, maybe some will have access to your point of view, think more about it, see those who are helpful. [Original] ---------------------------------------------- ---------------------------------------- I started from one and a half Since I learned Java, I started to study Java, I started to go to the Java version to see, from the beginning, I slowly arrived at the question of others, and I really feel good for a year. Nowadays some of the people think of the individual in the Java learning process, they will be shared, and I hope to help the later people to walk less, focus on the fingers, and quickly walk into Java's door. From the beginning, I started using Thinking in. Java 2nd, individuals still like this book, although they have not finished reading now ^ _ ^ Of course, because everyone's learning methods are different, some people like to see Core Java or Java How to Program, these are good books. Choose a suitable look, it is ^ _ ^ mainly talking about the few blocks of Java, can't be said to be very fine, because in fact, each piece can be said a lot, I just said that when these studies The focus or things you should pay attention to: Although it is an object-oriented language, the value type is still essential, if you have mastered C calculations and conversion rules in C, then I want to here There should be no problem, only two points need to pay attention: 1,14.0 This floating point constant is considered a double type, only plus the F suffix is a Float type; 2, the integer constant is considered INT, but in When compiling, you can think that the compiler will see it as a minimum value that can represent the number, so Byte B = 100; will not report the version type: I also turn it from C / C , in fact, the so-called reference type is in C already Reflected, there is a reference type when passing the parameters, considering from C, it is a pointer, but we can't make a hard exercise on it. So the focus here is: 1. All objects in Java are generated in the heap, so things that need to be similar to pointers point to it, that is, references; 2, we will use the reference to the object to reference, in addition to assignment In addition, there should be no operation is for the reference itself, this is the difference between C's pointer and Java's reference. Class and object: This is a large piece, there are many things, not to speak, say a few points: 1, class method, class attribute and member method, member attributes are loaded, initialized, and the same; 2, In the constructor, this () and super () usage; 3, subclass load process, initialization process, and constructive process; 4, overloading and overwriting; 5, overwriting the polymorphic problem ( Note: The application of the polymorphism is in the method, the parameter passed on the attribute is called: If the address value recorded in the reference type, it is as used as the value of the reference type variable, then all methods of Java are called It is time to pass the value of the value - numerical type, reference type transmission address.
IO stream: Compared with C, Java input and output, especially input is very troublesome, maybe because of the object-oriented consideration? do not know. Java offers a lot of IO streams, but we don't have to figure out all kinds of IOs. We only need to know what features each with the characteristics and characteristics, how the character stream is constructed on byte stream, almost all When the character stream is constructed, it is based on an existing byte stream, and its design makes we can set up the IO to one-section one section like a set of pipes until we want to Use the IO object (Example: BUFFEREDReader). When we use it later, we can check the API again. I think the few classes that mainly want to see are: FileReader, FileWriter, BufferedReader, with the System.out object, for the input of the text, it is enough Used, as for others, I don't think it is necessary to see so much. I used it again (I used Java for a year and a half, basically using bufferedreader and system.out) container: Personally, This is a big tool for Java programming. The class of my favorite is: arraylist (list) as a variable length array, hashmap (map) is used to create a lookup table, and I rarely use it, only in the use of HashMap I have used some. By familiarity with these two classes, the basic usage of List, SET and MAP can be grasped. In addition, it has several auxiliary classes to master: Iterator and Collectes. The Collectes class provides some universal tools for containers, such as sorting. In terms of sorting, it involves the comparator: Comparator. Can skilled using the Comprator class, let you sort your needs and your own customs. AWT and SWING: Personally, Java has very good encapsulation in the production of the graphics interface. I used to try to learn MFC, MFC will help you generate some code when generating a graphical interface, then let you have some code. The specified location is added to implement the function. I have a habit of this person. If I let me see something, then I don't know why you write, you won't go down, see that many of the code, naturally want to figure out Those who are, the result is a lot of knowledge, and then I only know that some of them are calling WinApi, and I will still use MFC now. Here is not to degrade MFC, I believe that MFC has a matter of people, but personal thinks that its package is not doing well, exposes too much things, maybe it can improve flexibility, but maybe I will have no deeper with it: (.
