Clone of Map Objects

Q

Jack developed a program by using a Map container to hold key/value pairs. He wanted to make a change to the map. He decided to make a clone of the map in order to save the original data on side. What do you think of it?

✍: FYIcenter

A

If Jack made a clone of the map, any changes to the clone or the original map would be seen on both maps, because the clone of Map is a shallow copy. So Jack made a wrong decision.

2007-03-03, 7563👍, 0💬

Troubleshooting NullPointerException
What is NullPointerException and how to handle it? When an object is not initialized, the default value is null. When the following things happen, the NullPointerException is thrown: Calling the instance method of a null object. Accessing or modifying the field of a null object. Taking the length of... 2007-03-03, 8873👍, 0💬

System.setOut() - Setting Standard Console Output to
How could Java classes direct program messages to the system console, but error messages, say to a file? The class System has a variable out that represents the standard output, and the variable err that represents the standard error device. By default, they both connected to the system console. But... 2007-03-03, 8871👍, 0💬

System.loadLibrary() - Loading DLL for JNI Interface
An application needs to load a library before it starts to run, how to code? One option is to use a static block to load a library before anything is called. For example, class Test { static { System.loadLibrary("myApp.dll" );} .... } When you call new Test(), the static block will be called first b... 2007-03-03, 8786👍, 0💬

Clone of Map Objects
Jack developed a program by using a Map container to hold key/value pairs. He wanted to make a change to the map. He decided to make a clone of the map in order to save the original data on side. What do you think of it? If Jack made a clone of the map, any changes to the clone or the original map w... 2007-03-03, 7564👍, 0💬

Well-Written Object Oriented Programs
What does a well-written Object Oriented program look like? A well-written object oriented program exhibits recurring structures that promote abstraction, flexibility, modularity and elegance. 2007-03-03, 7534👍, 0💬

Runable Interface and Thread
What is more advisable to create a thread, by implementing a Runnable interface or by extending Thread class? Strategically speaking, threads created by implementing Runnable interface are more advisable. If you create a thread by extending a thread class, you cannot extend any other class. If you c... 2007-03-03, 7082👍, 0💬

Variables in Double Quoted Strings
Would I use print "$a dollars" or "{$a} dollars" to print out the amount of dollars in this example? In this example, "$a dollars" or "{$a} dollars" will print the same result. But in other cases, you need to use curly braces to protect variable names. For example, for following PHP script will prin... 2007-02-27, 7039👍, 0💬

Virtual Functions in Java
Can you have virtual functions in Java? Yes, all functions in Java are virtual by default. This is actually a pseudo trick question because the word "virtual" is not part of the naming convention in Java (as it is in C++, C-sharp and VB.NET), so this would be a foreign concept for someone who has on... 2007-03-03, 6915👍, 0💬

What is Java
What is Java? Java is an object-oriented programming language developed initially by James Gosling and colleagues at Sun Microsystems. The language, initially called Oak (named after the oak trees outside Gosling's office), was intended to replace C++, although the feature set better resembles that ... 2007-03-03, 6341👍, 0💬

All rights in the contents of this web site are reserved by the individual author. fyicenter.com does not guarantee the truthfulness, accuracy, or reliability of any contents.