201671010115 Java experience in Java programming 11th week of 2016-2017-2

This week the teacher first took us to solve the Java 1th to 8th chapter left the problem. By explaining our weekly iterative approach to optimizing the ID and Calculator program, let us review the knowledge of the previous chapters and a deep understanding, like by name dictionary order, we want to sort out, but also to consider localization, and then find a fellow, we generally use equals () method , did not consider if the place of origin without my input province, he may not be my hometown, the result will be error, but the teacher told us the contains method, solved the problem, is the inclusion of the relationship, as long as the place of origin within the same name can be.

Then we learned the Java Nineth Collection, a collection, which contains multiple elements and provides an interface to the actions of the contained elements, which can consist of an object of the same type, or it can consist of different types of objects. The collection class has two main features: 1. (1) Only the object is accommodated. Unlike arrays, arrays can hold basic data type data and objects. (2). Flexibility. The basic data type data can be encapsulated into a wrapper object of that data type. 2 (1). The collection class holds objects that are instances of the object class, and once an object is placed in the collection class, its class information is lost, which is intended to be universal (2) of the collection class. The Objectl class is a superclass of all collection classes and can be generic, but re-sculpt. This is a common interface in the collection framework:

Where collection is the root interface in the collection hierarchy, and the JDK does not provide a direct implementation class for this interface; The list is an ordered set that can contain duplicate elements, be accessed by index, and set cannot contain duplicate elements and cannot be accessed by index The SortedSet interface provides a comparer object sorted in ascending order, the map contains key-value pairs, does not contain duplicate elements, and the SortedMap interface provides a comparer object sorted in ascending order, pressing key when sorting.

The most important question in this chapter is textbook 9-2, how to enter the user interface at the beginning of the run, try a lot of times can not, and then in the blog park to see the method provided by the teacher, try, sometimes can output such as right, but most of the situation does not output, I hope the teacher can guide

201671010115 Java experience in Java programming 11th week of 2016-2017-2