In java what is empty statement.Explain its usefulness?

Answer 1

An empty statement in Java is just that: a statement with nothing in it. There are typically two ways to represent this:

1. A single semicolon ;
   
2. An empty block {}

The usefulness of this type of statement is limited. The main use that I can think of is to fulfill the statement required for a loop structure.

Here is an example that I recently used:

while (sf(++n) != i);

This loop will constantly call the method sf with increasing values of n until the return value of sf(n) is equal to i. Each loop in Java must have some code to execute in the loop body. In this case, all necessary work is done in the condition, and so the mandatory loop body is an empty statement.

While there may be other (more clear) ways of writing this bit of code, this is an example of where that empty statement can be used.