The Study Of Object Oriented Software Complexity Metrics

The importance of Object Oriented Metrics should not be disregarded, especially in the era of increasingly use of Object Oriented technology. Nowadays, many Object Oriented Metrics is continually proposed, and is validated and mature gradually. However, there also are flaws in the metrics. To make the metrics easier to understand, to use, to direct people's development and design in better way, and to enhance the quality of software, further investigation and complement of the metrics need be done.The trait of Object Oriented software was analyzed. And some Object Oriented Metrics carrying weight was investigated and analyzed, such as CK metrics suits and MOOD metrics. The limitation of them, especially of the CK metrics, was summarized. In order to overcome the flaws of the metrics, improvement and complement were done. A method was proposed to calculate the Weighted Methods per Class (WMC) which the WMC was devided to three departments. In this way, the methods inherited from ancestral class can easily be counted into WMC of the class. At the same time, the limitation was got over. And the Depth of Inheritance Tree (DIT) was changed to count the number of all the ancestral classes. The flaw of DIT was overcome too. The feasibility to count all of the children class, including indirected inherited classes, to the NOC of the class was analyzed. The marrics of Encapsulation and Polymorphism at class level were proposed to complement the metrics suites.Furthermore, the metrics improved were applied to a metrics tool ~ C and C++ Code Counter (CCCC). According to the metrics improved, some metrics' algorithms were modified. The data of some software were collected by using this modified tool. And some analyses of the data were done.By adding the improved metrics into the metrics tool CCCC, or modifying the algorithms existed in the metrics tool, the improved metrics' feasibility and usability was validated. And theses can be a reference for other metric tool that how the metrics were caculated and how the tool developed. By collecting and analyzing the metrics data from software, some conclusions were got: not only the use of inheritance is deficient, but also it is lacking that the use of multiple inheritance.