java sample programs for interview

! = STR2STR1 = = str2So what's the output of the second program? The first way we talked about this is not to take the initiative to add the object to the string pool, but with an exception, calling the Intern () method manually will force a reference to the object to be added to the string pool. So the result of the second procedure isSTR1 = = str2"Question 4"differences and linkages between String pool and const poolKnowing the Java memory model, th

Java interview knowledge points (most of them have been seen, but they are still very useful ~~ Turn to stay) It's a classic thing, and it's everywhere. First, write the original article:First, let's talk about the differences between final, finally, and finalize. Final is used to declare attributes. Methods and classes indicate that attributes are unchangeable, methods cannot be overwritten, and classes c

Java interview questions Basic knowledge:1. simple principles and applications of the Exception Handling Mechanism in C ++ or Java. When a Java program violates the Java Semantic Rules, the Java Virtual Machine will indicate an er

is 443. The HTTP connection is simple and stateless; The HTTPS protocol is a network protocol built by the SSL+HTTP protocol for encrypted transmission and authentication, which is more secure than the HTTP protocol. HTTP uses port 80 by default, HTTPS uses 443 port by default How HTTPS ensures the security of data transmissionHTTPS is actually in the TCP layer and the HTTP layer between the SSL/TLS to secure the upper layer, the main use of symmetric encryption, asymmetric encrypt

Translated by Peter Seibel/Hao peiqiang This article is an interview with Joshua Bloch, Chief Java architect of Google, by Peter Seibel, expert of commmon lisp, talking about what books programmers should read, how they can quickly get familiar with a new language, and why they choose programming languages is like choosing a bar. 　　 　　Seibel: How did you start programming? Bloch: I think this is because of

in the heap instead of the stack, using the final decoration.46. What is GC? Why do you have a GC?GC is the meaning of garbage collection (Gabage Collection), memory processing is where programmers are prone to problems, forgetting or wrong memory recycling can cause program or system instability or even crashes, The GC functionality provided by Java can automatically monitor whether an object exceeds the scope to achieve the purpose of automatically

With the weakness of relational database in some aspects, to understand the characteristics and performance of the current popular database patterns will undoubtedly provide us with more choices and directions. Neo4j is a kind of graphic database, which has outstanding advantages in traversal and associated query. Cut the crap and get to know the neo4j before you let us try how to use neo4j in the program. NEO4J is developed in the Java lan

because they do not have any implementations.Code. After a class implements an interface, this class implements all the methods and attributes in the interface, and the attributes in the interface are under the default state are public static, and all methods are public by default. A class can implement multiple interfaces. 3. Advantages and principles of garbage collection. Two recovery mechanisms are also considered. A notable feature of Java is t

JAVA engineer interview questionsZookeeper I went to a company for an interview today. I felt dizzy with my brains. I didn't make a few algorithm questions. The questions were relatively simple. I should have prepared myself, but the status was not good, after the interview, I felt quite dissatisfied. I still had to wa

attention to the bottom of the implementation, the novice programmer as long as familiar with the basic use of methods, you can quickly develop on-line; but for senior programmers, the practice of internal strength is more important , such as algorithms, design patterns, underlying principles, and so on, only after these basic proficiency, in the development process can know its why, when problems can quickly locate the nature of the Problem.For Java

threads in sync. There are two ways to synchronize operations, method synchronization, and code block synchronization. When the Synchronized keyword is added to a method or block of code, it means that when a thread executes here, the object's lock is obtained first, and if the object is not locked, the thread adds a lock to the object and continues execution. While other threads are executing here, because the object is already locked, these threads will only wait for the lock on that object t

The topic comes from http://www.codeceo.com/article/201-java-interview-qa.html, the answer oneself search on the net, if have omission, welcome treatise. Learn together and make progress together. I. Java Fundamentals1. Why is the string class final? 2. HashMap The source code, the realization principle, the bottom structure.3. Tell me about some of the

1. Question: What happens if the main method is declared private?Answer: Can compile normally, but will prompt "Main method is not public" when run.2. Question: What is the difference between a reference and a pass in Java?Answer: A pass-through refers to an address rather than the value itself, and a pass value is a copy of the passed value.3. Question: What else to consider if you want to override the Equals method of an object?Answer: Hashcode.4. Q

The following is a list of videos related to this book, which will be updated dynamicallyChapter I.1 Video 1.1 The differences between JDK and JRE and JVM, install Java Development Environment 1.1.1 2nd page2 Video 1.2 Writing the first HelloWorld program 1.1.2 2nd page3 video 1.3 Developing slightly complex programs with function calls 1.1.3 5th page4 Video 1.4Debug Program 1.1.4 5th page5 video 1.5 Input

Alibaba JAVA Development interview FAQ Summary 4Three main features of java Encapsulation, inheritance, and PolymorphismDifferences between abstract classes and interfaces Java Abstract class:Classes modified using the abstract keyword are called abstract classes.Abstract methods are called abstract methods.Features:1.

Java Basic topics:1. After executing the following statements, the values of I and n are, int i=10;int n=i++%5;Results: i=11,n=02, for the following code which expression return value is True:bpublic class sample{Long length;Public Sample (Long L) {length=l;}public static void Main (String[]args){Sample S1,s2,s3;S1=new

Most programs need to output some text, such as mail messages, HTML files, or console output. However, computers can only process binary data in essence. programmers must make the software generate understandable texts. In this article, I will introduce why the template engine can save time when generating and outputting text. You will understand the advantages of templates and how to create efficient templates for different situations. Say goodbye to

type modifier (typespecifier). It is designed to modify variables that are visited and changed by different threads. Variables defined by the volatile type are extracted directly from the corresponding memory each time the system uses it, rather than using the cache. After using the volatile modifier member variable, the values of the variables that all threads see at any time are the same. A demo sample using volatile is given below.

use R2 in addition to R1, ... So go on until you can divide it evenly. The last non-0 divisor is (A, b).Time complexity O (logn).String s = "a" + "B" + "C" + "D" + "E"; how many objects are created?1 of them. "A" is a constant and only the literal value is stored.What are the output results of the following programs?String str = "ABCDEFGH";System.out.println (str.dubstring (3,5));Answer: "DE"What's the difference between StringBuffer and StringBuilde

The shortcut for generating text using Java programs-Linux general technology-Linux programming and kernel information. The following is a detailed description. Most programs need to output some text, such as mail messages, HTML files, or console output. However, computers can only process binary data in essence. programmers must make the software generate unders