If a class has multiple constructors, it can be said to have constructor ________.
- chaining
- overloading
- overriding
- polymorphism
When a class has multiple constructors with different parameter lists, it is said to have constructor overloading. Constructor overloading allows you to create multiple constructors in the same class, each with a different set of parameters. This is a form of method overloading specific to constructors. Constructor overriding is not a valid term in Java.
The ________ method is used to move the thread into the Ready/Runnable state.
- join()
- sleep()
- start()
- wait()
The "start()" method is used to move a thread into the Ready/Runnable state in Java. When a thread is started using "start()", it becomes eligible for execution, and the JVM schedules it for execution at the appropriate time.
When using PrintWriter, the method ________ can be used to flush the stream and check its error state.
- checkError()
- close()
- flush()
- write()
In PrintWriter, the method checkError() can be used to flush the stream and check its error state. This method is handy when you want to make sure that all data is written and no errors occurred.
Imagine you are developing a gaming application where the player's state needs to be saved and restored effectively. How would you manage the serialization of objects in a way that the player's progress, including scores and levels, is efficiently stored and retrieved?
- Serialize the entire game state, including scores and levels, into a single object for easy storage and retrieval.
- Implement a custom serialization process that selectively serializes only the necessary player progress data, reducing storage and transmission overhead.
- Use a database management system to store and retrieve player progress data, eliminating the need for custom serialization.
- Compress the serialized data before storage and transmission to reduce the data size and optimize efficiency.
In a gaming application, efficient serialization of player progress is essential. Option 2 is the correct choice because it allows for selective serialization, reducing overhead by serializing only the necessary data. Option 1 may result in unnecessary data serialization. Option 3 is a valid approach but involves a different technology (DBMS). Option 4 focuses on data size optimization but doesn't address the serialization process itself.
In Java, constructors have the same name as the _______.
- Class
- Method
- Package
- Variable
In Java, constructors have the same name as the class in which they are defined. This naming convention allows you to identify and use the constructor associated with a particular class.
A variable declared as double d = 10.3; occupies ________ bytes of memory.
- 16
- 2
- 4
- 8
In Java, a variable of type "double" occupies 8 bytes of memory. The "double" data type is a 64-bit floating-point type that can hold both integer and fractional values. It requires 8 bytes to store its precision and range, making it suitable for storing large and decimal numbers with high precision.
Envisage a situation where you are developing a high-throughput application where multiple threads are reading and writing to a data structure. Which collection would you select to store data and why?
- ArrayList
- ConcurrentHashMap
- HashSet
- LinkedList
In this scenario, a ConcurrentHashMap is the preferred choice. It's designed for concurrent access by multiple threads, making it suitable for high-throughput applications. Unlike ArrayList, LinkedList, and HashSet, it provides thread-safety without sacrificing performance. It achieves this through a mechanism that allows multiple threads to read concurrently while providing efficient locking for write operations.
The ________ method of HttpURLConnection class is used to make the connection to the remote object referred by the URL.
- connect()
- createConnection()
- makeConnection()
- openConnection()
To make a connection to the remote object referred to by a URL using HttpURLConnection, you use the openConnection() method. This method initializes and opens a connection to the specified URL. The other options are not standard methods for this purpose.
Which method is used to check if there are more lines of text to read from a BufferedReader object?
- canReadMore()
- hasMoreLines()
- hasNext()
- hasNextLine()
The BufferedReader class has a method called hasNextLine() that is used to check if there are more lines of text to read from the BufferedReader object. It returns true if there are more lines and false if the end of the file has been reached. The other options do not represent the correct method for this purpose.
How do you specify a timeout while trying to connect to a remote socket?
- setConnectionTimeout()
- setSoTimeout()
- setSocketTimeout()
- setTimeout()
To specify a timeout while trying to connect to a remote socket in Java, you can use the setSoTimeout() method on the Socket object. This method sets a maximum time for blocking operations, such as connecting or reading, to complete.