Java Programming/Keywords/assert
assert is a Java keyword used
to define an assert statement.
An assert statement is used to declare an expected boolean condition in a program.
If the program is running with assertions enabled, then the condition
is checked at runtime. If the condition is false, the Java runtime system
throws an AssertionError
Assertions may be declared using the following syntax:
assertexpression1[:expression2];
expression1 is a boolean that will throw the assertion if it is false. When it is thrown, the assertion error exception is created with the parameter expression2 (if applicable).
An example:
assertlist!=null&&list.size()>0:"list variable is null or empty"; Objectvalue=list.get(0);
Assertions are usually used as a debugging aid. They should not be used instead of validating arguments to public methods, or in place of a more precise runtime error exception.
Assertions are enabled with the Java -ea or -enableassertions
runtime option. See your Java environment documentation for additional options
for controlling assertions.