Assertion

Second form of Assertion

The second for of assertion takes another expression as an argument.

The syntax is,

assert expression1 : expression2;

where expression1 is the condition and must evaluate to true at runtime.

This statement is equivalent to

Enabling Or Disabling Assertion

By default assertion is not enabled, but compiler complains if assert is used as an identifier or label. The following command will compile AssertionDemo example with assertion enabled.

javac –source 1.4 AssertionDemo.java

The resulting AssertionDemo class file will contain assertion code.

Java Assertion Assertion facility is added in J2SE 1.4. In order to support this facility J2SE 1.4 added the keyword assert to the language, and AssertionError class. An assertion checks a boolean-typed expression that must be true during program runtime execution. The assertion facility can be enabled or disable at runtime.