java programming 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 try to do, and in the comment area to leave your answer, let everyone learn from each other.

Frontier Dream Workshop 2017-04-18 18:14 Most of the Java interview is divided into written and interview, the following issues are cutting-edge education small series according to the major IT enterprises interview asked the questions sorted out, such as the need for releva

Interview questions-java Design Pattern Example 1, adapter modeInvolves three roles: Target destination interface, Adaptee source role, adapter adapter,adapter The source interface to the target interface, inherits the source interface, and implements the target interface .Many examples of Java I/O operations are:Input

Java Algorithm interview questions: Separate them with carriage return or space in the answer file ., Package com. swift; import java. io. bufferedReader; import java. io. bufferedWriter; import java. io. fileInputStream; import

threads are not able to modify objects in the collection that is being traversed by iterator. At the same time, iterator allows the caller to delete elements from the underlying collection, which is not possible for enumeration.What is the difference between 17.HashSet and TreeSet?HashSet is implemented by a hash table, so its elements are unordered. The time complexity of the add (), remove (), contains () method is O (1).On the other hand, TreeSet is implemented by a tree-shaped structure in

1. What is a Java virtual machine? Why is Java called a "platform-agnostic programming language"?A Java Virtual machine is a virtual machine process that can execute Java bytecode. The Java source file is compiled into a bytecode

Java interview questions: how to sort HashMap key values In Java, HashMap is a data structure used to store "key" and "value" Information pairs. Unlike Array, ArrayList, and lists, it does not maintain the order of inserted elements.Therefore, sorting HashMap Based on keys or values is a very difficult

Java Questions Answers 1. What is the difference between an applet and an application? A Java application is made up of a main () method declared as public static void that accepts a string array argument, along with any other classes that main () CILS. it lives in the environment that the Host OS provides. A Java a

Huawei's Java interview questions Question No: 1 1. Public class test { Public static void changestr (string Str ){ STR = "welcome "; } Public static void main (string [] ARGs ){ String STR = "1234 "; Changestr (STR ); System. Out. println (STR ); } } Please write the output result: Question No: 2 1. Public class test { 2. Static Boolean Foo (char c ){ 3. syst

Java --------------- String basic interview questions Package stu. love. a;/* String: */public class StringDemo {public static void main (String [] args) {// the String is a constant. Once a String is created, the String ss = "hello"; ss = "world"; System. out. println (ss); // special case:/* when defining s2, go to the constant pool to check whether the string

Analysis:Store basic data types1. Create an arr reference in the stack2. Create an int array of length 3 in the heap and initialize it, assigning the default value of 03. Point an ARR reference to an int array4. Re-assign values to each int value in an int arrayStore reference type User1. Create a Userarr reference in the stack2. Create a user array of length 3 in the heap and initialize it, assigning a default value of NULL3. Point the Userarr reference to the user array4. Create a user1,user2

(throughput) collector?The throughput collector uses a parallel version of the new generation garbage collector, which is used for medium-sized and large-scale data applications. The serial collector is sufficient for most small applications, which require about 100M of memory on modern processors.7. In Java, when can objects be garbage collected?This object can be recycled when the object becomes inaccessible to applications that currently use the o

Java multi-thread interview questions 1. What is the difference between ArrayList and Vecoter? Similarities and differences between Array and ArrayListI. Differences between Array and ArrayList#1. variables of the Array type must be instantiated at the same time (at least the size of the Array must be initialized), while ArrayList can only be declared first.For e

. 28th, Programming question: Calculate 2 times 8 in the most efficient way? Programmers with a C background are particularly interested in asking such questions. 2 29th, two object values are the same (x.equals (y) = = true), but can have different hash code, this sentence is correct? No, there's the same hash code. 30th, when an object is passed as a parameter to a method, this method can change the

1. What is acitsag startup mode? For such a question, I will write an example myself. I will observe it to understand it. Activty supports four startup modes. Launchmode: Standard: each time a new activity window is started (New Operation) Singletop: if it is a target activity at the top of the stack, It will be opened directly. Otherwise, a new activity window (new) will be opened ). Singletask and singleinstance are basically the same. The difference is that if the root activity is set to sing

Controller: When the user clicks the Submit button in the Web page, the controller accepts the request and invokes the appropriate model to process the request. The corresponding view is then called according to the result of the processing to display the results of the processing. MVC process: First the controller accepts the user's request, invokes the corresponding model for business processing, and returns the data to the controller. The controller invokes the corresponding view to

Java multithreading interview questions Induction1. What are the implementation methods for multithreading? The following example shows the thread synchronization. (1) Java multithreading has two implementation methods: Inheriting the Thread class and implementing the Runnable interface. Thread implements the Runnable

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 program's run, and a run-time exception that represents an exception that may be encountered

, 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

One: The difference between Eclipse and MyEclipseA: 1 common: Both are used to develop Java projects, and software usage is almost identical2 MyEclipse is a fee-free software, which can develop both Java and Web projects, Eclipse can only develop Java projects, if you want to develop a Web project, but also need to add additional Eclipse Web plug-in (of course, c