java assert

The assert keyword in Java is used to test assumptions about a program's correctness during runtime. It is a debugging aid that helps to catch bugs early in the development process.

The syntax for using assert in Java is:

assert booleanExpression;

Here, booleanExpression is the condition that we want to test. If the expression evaluates to true, then the program continues to execute normally. However, if the expression evaluates to false, then an AssertionError is thrown and the program terminates.

We can also provide an optional message to be displayed with the AssertionError:

assert booleanExpression : errorMessage;

Here, errorMessage is a string that will be displayed along with the AssertionError if the condition is false.

Note that assertions are disabled by default in Java. To enable them, we need to pass the -ea (or -enableassertions) flag to the Java Virtual Machine when running the program.