java interview questions for 2 years experience

, which are tools for inserting some code error detection statements in the development and testing phases of a program. The assertion (Assert) syntax is as follows:1. Assert condition or 2, assert condition: expressionBoth forms will judge the Boolean "condition", if the result is False (false), the program is already in an incorrect state, the system throws Assertionerror, gives a warning and exits. In the second form, the expression is passed into

Java third week learning experience NBSP;NBSP;NBSP;NBSP;NBSP;NBSP;NBSP;NBSP;NBSP;NBSP;NBSP; Through this week's learning, I learned the core of Java, understood the definition of user-defined class, understood the declaration of objects, understood the use of constructors to initialize objects, used class properties and methods, and understood the purpose of th

learned that it is different from the keyboard to receive input and display results in the console interactive method of interaction, is a graphical user interface. This week, we mainly learned how to create a framework, how to frame it, how to display information in a component, and so on. Then we learned more about how to deal with 2D graphics, how to use colors, how to use special fonts, and so on in our after-school exercises. Then the feeling is that this interaction is really better than

Eighth Week Java Learning experienceThrough this week's study, relative to the previous week, the understanding of the clone, and the understanding of lambda more deeply, but still can not be familiar with the master, only mastered the relatively basic knowledge, for task seven, the task eight or can not complete the writing, can only write part, for the task of seven find out the hometown or have doubts , which has improved a lot more than last week.

Java Fifth Week learning experience through this week's study, the inheritance has a certain understanding, but not very familiar with the teacher in class according to the previous method of the fifth section of the understanding of the deeper into a bit, but also need a lot of code to grasp the deeper, because the method of sudden change, or there is a little unaccustomed, so now still in the adaptation

java Tenth Week learning experience Through the tenth week of learning, we learned about generic programming (Generic programming), which is also known as a parameterized type, that is, when defining classes, interfaces, and methods, the type parameter indicates the type of object that will be processed (such as the ArrayList Class). Generic programming means that writing code can be reused by many differ

Four weeks of study experienceThrough this week's study, the main content of the study is the fourth chapter involves the knowledge point, the teacher explained in detail about the integer separation of the program and about the circumference and area of the rectangle and circle procedures, the understanding of this parameter and static variable is not deep enough, still not use it, my program will not write, error rate is high, learning is very messy , the thinking is not clear.Last week's thir

defined in the Object class, so all classes inherit it. Subclasses override the Finalize () method to organize system resources or perform other cleanup work. The Finalize () method is called on the object before the object is deleted by the garbage collector.Second, Anonymous Inner class (anonymous inner Class) can extends (inherit) other classes, can implements (implement) interface (interface)? The anonymous inner class is an inner class without a name. Other classes cannot be extends (inher

) technology, so EJBS can be accessed remotely (across processes, across computers). However, EJBS must be in containers such as Webspere, WebLogic, and EJB clients never directly access real EJB components, but are accessed through their containers. The EJB container is the proxy for the EJB component, and the EJB component is created and managed by the container. The customer accesses the real EJB component through the container. Copyright NOTICE: This article for Bo Master original article, w

Java 11th Week learning experience through the 11th week of study, learned vetor, Stack,Hashtable class, edit run Arraylistdemo and linkedlistdemo two programs and Setdemo, the teacher in class analysis code, and let us experiment, master the better, but the book of the program 365 page 9-2set/settest not very understand, this code through the package import, I do not run out of results, do not know wher

). 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

can use @param annotations:import org.apache.ibatis.annotations.Param; publicinterface UserMapper { User selectUser(@Param("username") String username, @Param("hashedPassword") String hashedPassword); } You can then use the XML as follows (it is recommended to encapsulate a map as a single parameter to mapper):select id=”selectUser” resultType=”User”> select id, username, hashedPassword from some_table where#{username} and#{hashedPassword} select> Copyri

Java Nineth Week learning experienceThrough this week's study, learned the exception assertion and the log, has learnt to enable the assertion in the Eclipse compiler, but, regarding the exception, in the shorter teacher teaches the instance the procedure to be able to catch the exception, but in the Long program task Seven task Eight does not know is what kind of exception, No exception catch exception should be added, task nine does not define the L

| and | | The difference between and .| or for or operations to be judged as logical OR|| For short-circuit or only logical judgment when the left side is true no longer continues to judge and Computation as logic and for short circuit with when left for false no longer continues to judgeWhat kinds of data types are in Java?Divided into basic data types and reference data typesThere are 8 basic data typesReference data types are types such as arrays

; } public String GetClassID () {return classID; } public void Setclassid (String classID) {this.classid=classid; }}Complement:Studentpxgit log:Programming problem Code Hosting(Results of program operation)(1) Use the stack structure to output several items of an, where an=2an-1+2an-2,a1=3,a2=8(2) write a program to store student English scores in a list in a tree set so that they are automatically so

in turn because the parent does not know what variables and methods are in the subclass, and the class does not get the initialized parent class property, and the program goes wrong.(c) method overrides require that the subclass be exactly the same as the method of the parent class, otherwise the method overloads, in the subclass, to invoke the overridden method in the parent class, you can use the Super keyword, the sample code: Packagedemo;classparent{ Public voidShow () {System.out.println (

Question OneWrite a method that uses the above algorithm to generate a random integer of a specified number (for example, three). Answer: xn+1= (7^5*XN) mod (2^31-1)Program source code :import java.util.Random;import Java.util.Scanner; Publicclass Randomcount{ PublicStatic void Main (string[] args){Random rand=new random ();System. out. Print (" Please enter the number of random numbers you want to output:");Scanner in =new Scanner (System. in);int n

size of the chessboard, followed by a number of NXN 0 or 1.Output format:One of three outputs: X O NIL are all uppercase Letters.Input sample: 4 1 0 0 1 0 1 0 0 0 0 1 0 1 0 0 1 Sample Output: X Time limit: 500ms Memory limit: 32000kbImport java.util.Scanner; public class Hello{public static void main (string[] Args) {//TODO auto-generated method Stubscanner in=new Scanner (System . in); int N=in.nextint (); Th

This week, the teacher did not open a new curriculum, the first few weeks of the layout of the programming questions to answer, by following the teacher's ideas, found their own previously written code deficiencies, the program will not be written to have a certain grasp. But in the teacher let us extrapolate, their own writing a similar program when very difficult, error rate is high, knowledge messy, do not make the book knowledge into ability. And

It's the sixth week of Learning Java, and in this week's study, you know that interfaces cannot construct interface objects, but you can declare interface variables to point to a class object that implements the interface. to declare a class to implement an interface, you need to use the keyword implomnts,The purpose of the Commparator interface is to handle the operation of strings sorted by length. In task six, the lambda expression format is mast