CSC/ECE 517 Fall 2010/ch6 6b HA

Assertions in Object Oriented Language

In most of the programming languages assertions are statements that enables developers to test assumptions about the code they write. For example, if a developer writes a function that checks if two strings are equal or not, he might assert that the lengths of the strings are equal. Assertions are always made using a Boolean expression which a developer assumes will be true when the assertion gets executed. If the assertion is false then error will be thrown at the runtime. By doing this verification on that Boolean expression, assertion confirms developer’s assumptions about the program behavior and hence increase the confidence that an application is as per the requirement and free of errors. Research has shown that by writing assertions while a developer is programming is one of the efficient ways to detect and fix bugs. Also, assertions acts as a documentation to the inner working of the code and hence improves the maintainability of the code which is an important aspect of software engineering.