Java Programming for Complete Beginners - Java 16 - Step 06 - Implementing an Example with ConcurrentHashMap

The video tutorial discusses the importance of thread safety in programming and introduces the use of concurrent maps to achieve it. Initially, a character counting problem is implemented using a hash table, which is not thread-safe. The tutorial then introduces LongAdder for atomic operations and explains the limitations of non-thread-safe code. Finally, the video demonstrates how to use a ConcurrentHashMap and lambda expressions to ensure thread safety and atomic operations, replacing the previous code with a more efficient solution.

What is the primary reason for using a concurrent map in multi-threaded environments?

• To reduce memory usage

• To improve code readability

• To ensure thread safety

• To increase execution speed

Why is LongAdder preferred over Long for counting operations in a multi-threaded context?

• It is faster in single-threaded applications

• It provides atomic increment operations

• It is easier to implement

• It uses less memory

What is the main drawback of using a simple hash table in a multi-threaded environment?

• It is not thread-safe

• It is slower than other data structures

• It cannot store null values

• It requires more memory

What issue arises when two threads update a shared variable without synchronization?

• The variable may become null

• The update may be lost

• The variable may double in value

• The update may happen twice

Which method in ConcurrentHashMap helps in ensuring atomic operations when a key is absent?

• putIfAbsent

• computeIfAbsent

• merge

• replace

What is the advantage of using concurrent collections?

• They use less memory

• They are faster in single-threaded applications

• They make operations atomic

• They are easier to debug

How does ConcurrentHashMap differ from a regular HashMap?

• It allows null keys

• It is synchronized for thread safety

• It uses less memory

• It is faster in single-threaded applications