CORE JAVA Interview Questions-Part5

Question: What modifiers may be used with an inner class that is a member of an outer class?

Answer: A (non-local) inner class may be declared as public, protected, private, static, final, or abstract.

Question: How many bits are used to represent Unicode, ASCII, UTF-16, and UTF-8 characters?

Answer: Unicode requires 16 bits and ASCII require 7 bits. Although the ASCII character set uses only 7 bits, it is usually represented as 8 bits. UTF-8 represents characters using 8, 16, and 18 bit patterns. UTF-16 uses 16-bit and larger bit patterns.

Question: What are wrapped classes?

Answer: Wrapped classes are classes that allow primitive types to be accessed as objects.

Question: What restrictions are placed on the location of a package statement within a source code file?

Answer: A package statement must appear as the first line in a source code file (excluding blank lines and comments).

Question: What is the difference between preemptive scheduling and time slicing?

Answer: Under preemptive scheduling, the highest priority task executes until it enters the waiting or dead states or a higher priority task comes into existence. Under time slicing, a task executes for a predefined slice of time and then reenters the pool of ready tasks. The scheduler then determines which task should execute next, based on priority and other factors.

Question: What is a native method?

Answer: A native method is a method that is implemented in a language other than Java.

Question: What are order of precedence and associativity, and how are they used?

Answer: Order of precedence determines the order in which operators are evaluated in expressions. Associatity determines whether an expression is evaluated left-to-right or right-to-left

Question: What is the catch or declare rule for method declarations?

Answer: If a checked exception may be thrown within the body of a method, the method must either catch the exception or declare it in its throws clause.

Question: Can an anonymous class be declared as implementing an interface and extending a class?

Answer: An anonymous class may implement an interface or extend a superclass, but may not be declared to do both.

Question: What is the range of the char type?

Answer: The range of the char type is 0 to 2^16 - 1.