java data structures interview questions

A few days ago in the Java interview problems encountered, this is only part of the problem, there are many questions in the interview about data structures and algorithms. Here to summarize, hope that the ability of people can tr

COSCO Java interview question zzz COSCO Java interview questions Java training materialsI. Java language1. Three basic features of object-oriented2. Concepts and differences between met

) {MapNewHashmap(); Premiumphone.put ("Apple", "IPhone"); Premiumphone.put ("HTC", "HTC One"); Premiumphone.put ("Samsung", "S5"); Iterator Iterator=Premiumphone.keyset (). iterator (); while(Iterator.hasnext ()) {System.out.println (Premiumphone.get (Iterator.next ())); Premiumphone.put ("Sony", "Xperia Z"); } } }"Main" java.util.ConcurrentModificationException at java.util.hashmap$hashiterator.nextentry (Unknown SOURCE) at Java.util.hashmap$keyiterator.next (Unknow

system quickly fails to make a false error alarm immediately. In Java, quick failures are related to iterators. If a iterator is created on the collection object, other threads are "structured" to modify the collection object, and the concurrent Modification exception (Concurrentmodificationexception) is thrown.8, how to make HashMap synchronization?The HASHMAP can be synchronized by using map m = Collections.synchronizedmap (HASHMAP).9, when to use

The Java Collection framework is the foundation of the Java programming language and is an important knowledge point in the Java interview. Here, I've listed some important questions and answers about the Java collection.In additi

The Java Collection framework is the foundation of the Java programming language and is an important knowledge point in the Java interview. Here, I've listed some important questions and answers about the Java collection.In additi

to sort two input parameters, return a negative number, 0, and a positive number indicates that the first parameter is less than, equal to, greater than the second argument. The Equals () method requires an object as a parameter that determines whether the input parameters are equal to comparator. This method returns true only if the input parameter is also a comparator and the input parameter is the same as the current comparator's ordering result.12. What is the

, and future to implement threads with return resultsThe Executorservice, callable, and future three interfaces are actually executor frameworks. The thread that returns the result is a new feature introduced in the JDK1.5, and with this feature it is no longer necessary to get the return value. And it can be flawed if it is achieved.A task that can return a value must implement the callable interface. Similarly, a task without a return value must implement the Runnable interface.After performin

adapter pattern? Ø database How are you usually optimized, what other tools are used to optimize no, how to use the Ø Now there is a lot of tables to correlate the query SQL, the child table data is very much, then you only from the SQL point of view of the SQL statement optimization, do not need to consider the index, predicate Ø you don't have a Java project, do you? Ø your major is to control the direct

115 Java Interview Questions and answers-ultimate list (I), 115 java Object-Oriented Programming (OOP) Java is a computer programming language that supports concurrency, class-based, and object-oriented. The advantages of object-oriented software development are listed bel

; k ) TestFunction (k, J, i);On the basis of scenario one, this scheme puts the instantiation of the cyclic variables out of the loop, which can further reduce the number of instances of the related cyclic variables, and the scheme time-consuming situation is as follows: Variable Instantiation (number of times) Initialization (number of times) Comparison (number of times) Self-increment (number of times) I 1 1 10 1

values that cannot be changed. The string provided by this StringBuffer class is modified. You can use StringBuffer when you know that character data is going to change. Typically, you can use Stringbuffers to dynamically construct character data.5. What are the similarities and differences between abnormal operation and general anomaly?An exception represents an unhealthy state that may occur during a pro

First, let's talk about the differences between final, finally, and finalize.　　Second, can anonymous inner class (anonymous internal class) be extends (inherited) other classes, or implements (implemented) interface (Interface )?　　Third, the difference between static nested class and inner class is that the more you say, the better (the more general the interview questions are ).　　Fourth, the difference bet

Java Collection related interview questions and answers Interview questions1.JavaWhat is a collection frame? What are some of the advantages of a collection framework? There are collections in each programming language, and the original Java version contains several collect

Dark Horse programmer ---- java-based operators, keyboard input, if switch statements, related Interview Questions, ---- javaswitch ------ Java training, Android training, iOS training, and. Net training. We look forward to communicating with you! ------- 1: Operator (master)(1) Arithmetic Operators A: +,-, *,/, %, ++

ArticleDirectory 17 questions about massive data processing and bit-Map Preface Part 1 and 15 interview questions on massive data processing Part 2: BTI-map for Massive Data Processing

dispatch and dispatch, and a smaller unit that can run independently than a process. Thread's StrokeThe sub-scale is less than the process, which makes the multi-threaded procedure highly concurrency, and the process typically has independent memory units at execution time, while the threads can share memory. Programming with multithreading often leads to better performance and user experience,But multithreaded programs are unfriendly to other programs because they may consume more CPU resource

Java interview questions: Implementation of stacks and queues During the interview, stacks and queues are often checked in pairs. This article includes the following stack and queue test content: 1) stack Creation 2) create a queue 3) Two stacks implement one queue 4) two queues implement one stack 5) design the stack

Android development interview: 4. Common basic Java questions, androidjava Follow finddreams blog: http://blog.csdn.net/finddreams/article/details/44403041Because Android is programmed using the Java language, it is necessary for us to fully master the Java foundation for A

After JDK5, Java provides a more convenient security mechanism that uses lock locks for thread-locked operations and release operations without using synchronized . More clear. Example:Lock lock=new Reentrantlock ();Lock.lockCode that needs to be lockedLock.unlockWhy is lock more secure? Because synchronized may cause deadlock phenomenon, specifically about the deadlock phenomenon can refer to the operating system, there is no more to say.Summarize th