Thread: Use of assertion in java

I am unable to know the assertion in java. I do not know what the use of assertion in java is. I have referred different java programming books but did not get sufficient information over this. If you know the use of assertion in java, then please let me know that. Any help would be highly appreciated.

Assertions include Boolean expressions that define the accurate state of your program at particular points in the source code. Assertions can be used to discover errors that may otherwise go unnoticed. Use assertions for internal consistency checks, i.e. to show you screwed up, not the user of your class. Assertion used to presents an overview of design by contract.