How can we handle SQL exceptions that may occur during the execution of a JDBC program?
- Ignore them and let the program continue
- Use assert statements to handle exceptions
- Use if-else statements to handle exceptions
- Use try-catch blocks to catch and handle exceptions
SQL exceptions in a JDBC program should be handled using try-catch blocks. Ignoring them can lead to unexpected program behavior, and try-catch allows you to gracefully handle errors, log them, or take corrective actions. The other options are not recommended approaches for handling exceptions in JDBC.
To write primitive data types like int or double to a file in a machine-independent way, you might use ________.
- DataOutputStream
- FileInputStream
- ObjectInputStream
- ObjectOutputStream
To write primitive data types to a file in a machine-independent way, you can use DataOutputStream. It provides methods for writing different data types to a file while ensuring that the data can be read back correctly.
How does Java handle the division of an integer by zero?
- It returns NaN (Not-a-Number).
- It returns a positive or negative infinity value, depending on the sign of the numerator.
- It returns zero.
- It throws an ArithmeticException.
In Java, dividing an integer by zero results in an ArithmeticException being thrown at runtime. Division by zero is mathematically undefined, and Java handles it by throwing this exception to indicate the error. Options 1, 3, and 4 are incorrect because they don't accurately represent how Java handles this situation.
A JDBC ________ provides the necessary methods to interact with the database.
- Connection
- Driver
- ResultSet
- Statement
In JDBC, a Connection is used to establish a connection to a database. It provides the necessary methods to interact with the database, such as executing SQL queries and managing transactions. A JDBC Driver is responsible for establishing the connection, but the Connection object is what allows you to interact with the database.
If a superclass method does not throw an exception, can the overridden method in the subclass throw an exception?
- No, it cannot throw any exception
- No, it cannot throw any exception
- Yes, it can throw any exception
- Yes, it can throw any exception
In Java, if a superclass method does not declare any exceptions, the overridden method in the subclass cannot throw checked exceptions that are broader in scope than those of the superclass method. This rule is in place to ensure that the subclass does not introduce unexpected exceptions.
The ________ keyword can be used to print multi-dimensional arrays in a deep-to-string manner.
- deepToString
- display
- toString
In Java, the Arrays.deepToString() method can be used to print multi-dimensional arrays in a deep-to-string manner. This method recursively converts the array into a string representation, including nested arrays, making it useful for debugging and displaying complex data structures.
Which loop structure should be used when the number of iterations is known in advance?
- do-while loop
- for loop
- if statement
- while loop
The for loop is ideal when you know the number of iterations in advance. It consists of an initialization, condition, and increment/decrement statement. This loop is suitable for iterating over arrays, collections, or any situation where the number of iterations is predetermined.
What is the primary purpose of a constructor in Java?
- To create objects of the class.
- To define the class methods.
- To initialize the class variables.
- To provide a way to destroy objects of the class.
In Java, a constructor's primary purpose is to initialize the class's instance variables when an object is created. Constructors don't define class methods or create/destroy objects; that's not their primary role.
A ________ block will always execute, whether an exception is thrown or not.
- catch
- finally
- throw
- try
The finally block is used to define a block of code that always executes, regardless of whether an exception is thrown or not. It's commonly used for cleanup operations such as closing files or releasing resources.
The method getInputStream() returns an input stream that reads from the ________.
- URL
- output stream
- remote object
- socket
The getInputStream() method in Java returns an input stream that allows you to read data from the remote object referred to by the URL. This is commonly used in HTTP connections to read the response data from a server. The other options do not represent what this method returns.