Core JAVA Interview Questions & Answers-4

1. What is synchronization and why is it important? - With respect to multithreading, synchronization is the capability to control the access of multiple threads to shared resources. Without synchronization, it is possible for one thread to modify a shared object while another thread is in the process of using or updating that object’s value. This often leads to significant errors.
2. Is null a keyword? - No, The null value is not a keyword.
3. How many bits are used to represent Unicode, ASCII, UTF-16, and UTF-8 characters? - Unicode requires 16 bits and ASCII require 7 bits. while 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.
4. What are wrapped classes? - Wrapped classes are classes that allow primitive types to be accessed as objects.
5. What is a native method? - A native method is a method that is implemented in a language other than Java.
6. What is the catch or declare rule for method declarations? - 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.
7. What is the range of the char type? - The range of the char type is 0 to 2^16 - 1.

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