Data generator is a system that automatically generates test data for a given program. Data generators are normally classified into three classes: random, path-oriented, and goal-oriented test data generators. A typical test data generator system, which consists of three parts: program analyzer, path selector and test data generator. The source code is run through a program analyzer, which produces the necessary data used by the path selector and the test data generator. The selector inspects the program data in order to find suitable paths.