Sjberg et al. the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, See further details. acknowledge that you have read and understood our, Data Structure & Algorithm Classes (Live), Data Structure & Algorithm-Self Paced(C++/JAVA), Android App Development with Kotlin(Live), Full Stack Development with React & Node JS(Live), GATE CS Original Papers and Official Keys, ISRO CS Original Papers and Official Keys, ISRO CS Syllabus for Scientist/Engineer Exam, Spring Boot - Start/Stop a Kafka Listener Dynamically, Parse Nested User-Defined Functions using Spring Expression Language (SpEL), Split() String method in Java with examples, Object Oriented Programming (OOPs) Concept in Java. Madhwaraj, K.G. Well, its easy for the primitive types, not for the objects. 2021. This program compiles and executes successfully. For 42 software systems, only the last released version was included in the experiment, while for the remaining 3 systems, all versions from the release history were included. Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above. Because we had a moderate sample size (, For each software system under study, values of the Index variants are visually presented in, The differences between the values of Index variants are evaluated in, The scatter plot matrix representation with pairwise correlation analysis is shown in, To further analyze the multivariate relationships based on the Pearson Correlation Coefficient between the seven Index variants, multidimensional scaling was used to reduce the dimensions of the data to two. Every class in java has one parent class that is Object class and it has equals () method to compare two any objects. Overriding follow the convention for the hashCode() method that states, the equal object must have equal hash code. Object-oriented programming paradigm for damage tolerant evaluation of engineering structural components. The Java Object class provides the two important methods to compare two objects in Java, i.e. This issue has already been noted by systematic literature reviews conducted in the research field [, In the literature, the Maintainability Index has been used as a measure of maintainability extensively researched from various perspectives. Available online: Puntigam, F. Interfaces of Active Objects with Internal Concurrency. Please mail your requirement at [emailprotected] Duration: 1 week to 2 week. Multiple requests from the same IP address are counted as one view. Use Collections.min () method and store the return value in min variable. It returns a randomly generated hash code value of the object that is unique for each instance. The above program produced the output saying both e1, e3 objects are not the same even though both objects are having the same values. Most of the time, we want to compare the actual values inside the objects. articles published under an open access Creative Common CC BY license, any part of the article may be reused without In Proceedings of the 35th Annual ACM Symposium on Applied Computing, Brno, Czech Republic, 30 March3 April 2020; Association for Computing Machinery: New York, NY, USA, 2020; pp. In Proceedings of the 2018 International Conference on Innovations in Information Technology (IIT), Al Ain, United Arab Emirates, 1819 November 2018; pp. We will be creating two objects and set the first object to "BMW" and the other object to "AUDI". We limited our selection to well-defined variants (i.e., variants with an adequate description of the metrics needed for computation, the process of the metrics collection, and the process of Index calculation) that are commonly used in existing research on object-oriented software. C4 Software Technology Reference Guide-A Prototype, Statistical Power Analysis for the Behavioral Sciences. 2021. SomeClass) but I can still use a plain vanilla unit testing framework. Method 1: One obvious approach is to write our own sort () function using one of the standard algorithms. I propose another option one that could be useful , especially when theres a need to compare different properties in different tests. Create two variables, minimum and maximum. Disclaimer/Publishers Note: The statements, opinions and data contained in all publications are solely The next threat to internal validity is related to the methods of data analysis used. However, it is still unclear how different Index variants compare when applied to software systems. Let us look then at the code inside Object.equals() method and understand its internals. Available online: Virtual Machinery. After that, we have invoked the hashCode() method using objects. Applied Sciences. let us create a new Employee e3 object with the same values as e1. The objectives of this work were twofold: first, to highlight distinct variants of the Maintainability Index employed to measure maintainability in object-oriented systems and assess the results of variants when applied to measure the maintainability of the same subject software; second, to research the results of the variants when applied to measure the maintainability of a software system to compare the system with other systems. All systems studied were open-source and based on the Java programming language. To understand and manage software under development and maintenance better, several maintainability measures have been proposed. Fioravanti, F.; Nesi, P. Estimation and prediction metrics for adaptive maintenance effort of object-oriented systems. Then, we will compare the objects by using the BeanComparator by calling its compare() method. Let us add the customized logic for object comparisons. Since the default behavior ofEqualsis to compare references (in case of classes) the result is a fail. This means that when focusing on finer-grained results posed by the Index, the selection of the Index variant has even more of an impact on the maintainability perception. All rights reserved. It is not necessary that if the two objects are unequal according to equals() method, then invoking the hashCode() method on these two objects may produce distinct integer value. [. Example 1: The above implementation along with usage of hashCode(): How to Compare Two TreeMap Objects in Java? In Proceedings of the Evaluation of Novel Approaches to Software Engineering: 15th International Conference, ENASE 2020, Prague, Czech Republic, 56 May 2020; Revised Selected Papers 15. [. The Maintainability Index was calculated for each software system under study using seven variants: Next, data analysis on the acquired data was performed using IBM SPSS Statistics 28 and Python 3.7.6. with the matplotlib, NumPy, pandas, SciPy, seaborn, and scikit-learn libraries. Streansk, P.; Chren, S.; Rossi, B. Modeling Design/Coding Factors That Drive Maintainability of Software Systems. ; Johannessen, E.B. How do different Maintainability Index variants perform when utilized for maintainability measurement between different software systems? Faculty of Electrical Engineering and Computer Science, University of Maribor, Koroka Cesta 46, 2000 Maribor, Slovenia. 16. How do different Maintainability Index variants perform when utilized for maintainability measurement between versions of the same software system? Compute all the permutations of the string. Several aspects can impact the softwares maintainability, including the codes complexity, the softwares size, and the presence of documentation and comments that help describe the code. Therefore, it is advisable not to use this method in comparing objects without overriding it. To answer RQ1, descriptive statistics were initially used to describe the values of each Index variant and to gain a general understanding of the distribution of the data. In the above program, we have two strings namedstyle and style2 both containing the same world Bold. The original three-metric Maintainability Index (further referred to as. If a class implements Comparable then such comparator may be used in compareTo method: @Override public int compareTo (Person o) { return Comparator.comparing (Person::getFirstName) .thenComparing (Person::getLastName) .thenComparingInt (Person::getAge) .compare (this, o); } Share Improve this answer edited Aug 8, 2017 at 15:28 community wiki In this program, you'll learn to compare two strings in Java. We rarely compare the object references in real projects. = median, Std. Comparing Maintainability Index, SIG Method, and SQALE for Technical Debt Identification. ; Atkinson, G.G. ; Symeonidis, A.L. Checking the hash values using hashCode() before entering the equals() reduces the time taken to produce the solution drastically. To explore the variants and understand how they compare when evaluating software maintainability, an experiment was conducted with 45 Java-based object-oriented software systems. You probably think comparing two objects in JavaScript is easy. In Proceedings of the 19th International Conference on Mining Software Repositories, Pittsburgh, PA, USA, 2324 May 2022; Association for Computing Machinery: New York, NY, USA, 2022; pp. The differences in Index variants values are the most notable when looking at the finer-grained results derived from different Index variants. Sci. In Proceedings of the International Conference on Data Engineering and Communication Technology, Maharashtra, India, 1011 March 2017; Satapathy, S., Bhateja, V., Joshi, A., Eds. [. But, if the Class has so many properties, the code will be . In this short tutorial, we'll solve this using Gson, a JSON serialization\deserialization library that can do a deep comparison between JSON objects. ; Rana, A. Please note that many of the page functionalities won't work as expected without javascript enabled. Due to this behavior there are many (myself included) who suggest overridingEqualsto make sure that the actual values are compared, which could be a problem if our production code cannot be changed to accommodate our tests. Remember: When we override the equals() method, it is necessary to override the hashCode() method. In Proceedings of the 27th International Workshop on Software Measurement and 12th International Conference on Software Process and Product Measurement, Gothenburg, Sweden, 2527 October 2017; Association for Computing Machinery: New York, NY, USA, 2017; pp. And since book4 and book5 all point to the same object instance, book1, so book 4 === book5 is true. Singh, N.; Singh, D.P. Vijaya; Sharma, S.; Batra, N. Comparative Study of Single Linkage, Complete Linkage, and Ward Method of Agglomerative Clustering. The JHawk tool was used to extract the source code metrics, as it is commonly used for metrics extraction of Java software. In this case, the result of the comparison is false. In the previous example, we have discussed how to sort the list of objects on the basis of a single field using Comparable and Comparator interface But, what if we have a requirement to sort ArrayList objects in accordance with more than one field like firstly, sort according to the student name and secondly, sort according to student age. whether they are the same object or not. Finally, How to compare and sort the List of employees using the Collections.comparing() method. If you instead change the program to use equality operator, you'll get Not Equal as shown in the program below. 581591. Brito e Abreu, F.; Melo, W. Evaluating the impact of object-oriented design on software quality. Construction and testing of polynomials predicting software maintainability. https://doi.org/10.3390/app13052972, Heriko T, umak B. One or more elements from. Arisholm, E.; Briand, L.C. In Proceedings of the 2019 International Conference on Machine Learning, Big Data, Cloud and Parallel Computing (COMITCon), Faridabad, India, 1416 February 2019; pp. If you are not calling the Collections.sort() method then our comparator logic will not be executed. ; Springer: Singapore, 2017; pp. Comparison of Maintainability Index Measurement from Microsoft CodeLens and Line of Code. The object-oriented paradigm is one of the dominant programming paradigms for modeling and developing software. To overcome this and compare JSON data semantically, we need to load the data into a structure in memory that's not affected by things like whitespace or by the order of an object's keys. In Proceedings of the 2018 International Conference on Electrical Engineering and Informatics (ICELTICs), Banda Aceh, Indonesia, 1920 September 2018; pp. No special There are several Index variants that differ in the factors affecting maintainability (e.g., code complexity, software size, documentation) and their given importance. By using this website, you agree with our Cookies Policy. During maintenance, software systems undergo continuous correction and enhancement activities due to emerging faults, changing environments, and evolving requirements, making this phase expensive and time-consuming, often exceeding the initial development costs. Here is the string comparison which is possible in Java. ; Goldinger, S.D. Next, focusing on identifying any significant differences between the variants, the pairwise differences between Index variants were assessed. The 2021 State of the Octoverse. Convert a String to Character Array in Java. For instance, it may be on roll no, name, age, or anything else. Therefore, it is essential to understand how maintainable a software system is as it is being developed. MDPI and/or In Java, hash code is a 32-bit signed integer value. Example 1: Although equals() method can be used to compare the values of two strings, it is not really useful by default to compare two objects without overriding it. = standard deviation. Learn to code interactively with step-by-step guidance. and B.. Granja-Alvarez, J.C.; Barranco-Garca, M.J. A Method for Estimating Maintenance Cost in a Software Project: A Case Study. Illustration: An example to illustrate an object of a class: // Here, chair and sofa are two objects of the class Furniture. Feature papers represent the most advanced research with significant potential for high impact in the field. = average, Med. 2021. How to add an element to an Array in Java? Paper should be a substantial original Article that involves several techniques or approaches, provides an outlook for Stack Overflow Developer Survey. When we run the program (HashCodeExample.java) with the above code snippet, we get the following output. The difference between those two lists would give us the students who didn't pass the exam. In this class, we have created two instances of the Employee class i.e. and B.. Now, you will write a function to compare two objects. Were in fact testing oneSomeClassthat happen to have two properties. Maua, G.; Galinac Grbac, T. Co-evolutionary multi-population genetic programming for classification in software defect prediction: An empirical case study. 121124. The reason is that deep down inside our assert have no idea what is an equal object and so it runsObject.Equalsand throws an exception in case of failure. Elish, M.O. It can be observed that, in the case when comparing the maintainability between releases of the same software system, i.e., when changes in the source code are small, the Index variants tend to be more prone to non-consistency in the maintainability comparisons. The studys results showed that when comparing maintainability measurements from several Index variants, the perception of maintainability could be impacted by the choice of the Index variant used. You compare Java primitives (int, long, double, etc.) const obj1 = . In terms of practical implications, software practitioners can use the results of this research to guide their selection of the most-appropriate Index variant for assessing the maintainability of their software systems in an efficient and effective manner. To meet the above-specified objectives, the following two research questions (RQs) were formulated: How do different Maintainability Index variants perform when utilized for the maintainability measurement of a single object-oriented software system? Another threat to external validity is the set of Index variants studied. Even though the findings are likely valid for software based on other object-oriented languages, further research is needed to confirm them. Anyone who has ever Googled (Binged?) On the other hand, equals() method compares whether the value of the strings is equal, and not the object itself. We can, therefore, compare them: assertThat (planes1).isNotSameAs (planes2); To sum up, in this case, we have two arrays in memory that contain the same String values in exactly the same order. In this way, many comparisons between two objects need not go through the comparison of every value within them. Software code maintainability: A literature review. Pratap, A.; Chaudhary, R.; Yadav, K. Estimation of software maintainability using fuzzy logic technique. Agree All authors have read and agreed to the published version of the manuscript. 2. Maintainability as a software characteristic is of paramount importance in software development because it substantially affects the long-term expenses associated with a software system. Java Program to Compare Two Objects Difficulty Level : Medium Last Updated : 16 Jun, 2021 Read Discuss Courses Practice Video An object is an instance of a class that has its state and behavior. De Stefano, M.; Iannone, E.; Pecorelli, F.; Tamburri, D.A. Another potential area of research is to conduct replication studies of existing work by analyzing the results from the perspective of using Index variants other than the one primarily selected. Welker, K.D. String comparison in Java is a feature that matches a sequence of characters to a string. By comparing two objects, the value of those objects isn't 1. In the following example, we have created constructor of the Double and Long class and passes corresponding values, as an argument that stored in their objects, respectively. A Tale of Two Development Approach: Empirical Study on The Maintainability and Modularity of Android Mobile Application with Anti-Pattern and Model-View-Presenter Design Pattern. In Proceedings of the 2015 41st Euromicro Conference on Software Engineering and Advanced Applications, Madeira, Portugal, 2628 August 2015; pp. In the example above, person1 and person2 have the same properties and values, so JSON.stringify(person1) === JSON.stringify(person2) is true. To learn how to compare strings in Java, you can use the methods provided by the following classes. Learn Java practically [. Based on their characteristics, behavior, and interrelationships, the variants were divided into two distinct clusters, i.e., variants that do not consider code comments in their calculation and those that do. Dahiya, S.S.; Chhabra, J.K.; Kumar, S. Use of genetic algorithm for software maintainability metrics conditioning. You should not use == (equality operator) to compare these strings because they compare the reference of the string, i.e. Visual Studio. Syntax: public boolean equals (Object obj) It returns true if all values of the two objects are the same. These findings reinforce the importance of carefully considering which variant of the Index to use for the maintainability assessment, namely taking into account whether or not code documentation should be considered. Sjberg, D.I.K. [, Some studies have compared the well-established Maintainability Index variant with alternative software quality measures with the aim of validating new measures. ; funding acquisition, B.. *; class GFG { public static void main (String [] args) { In Proceedings of the Software Engineering Productivity Conference, Salt Lake City, UT, USA, 7 April 1992; pp. Though the values of dog1 and dog2 are the same, equals() method always checks the reference of the two objects i.e if both the objects passed refer to the same object or not and not their values. Each Java object is associated with the hash code. 5: 2972. 2.2. As you can see, the result book1 === book2 is false despite the equality of their content because they have different references. Moreover, when comparing the maintainability of software systems using different variants of the Index, very similar outputs can be expected for all variants without the comment part and all variants with the comment part. (string1 == string2) it returns 0. if (string1 < string2) it returns a negative value. First, in, The results of the correlation analysis were further analyzed through multidimensional scaling to gain a deeper understanding of the relationships between the Index variants. 261282. Join our newsletter for the latest updates. Microsoft. Java Comparable must define o1.compareTo (o2) used to implement natural ordering of objects we must modify the class whose instances we want to sort it's in the same class only one implementation Questioning software maintenance metrics: A comparative case study. In the second comparison, equals () checks to see whether the passed object is null, or if it's typed as a different. We can compare two HashMap by comparing Entry with the equals () method of the Map returns true if the maps have the same key-value pairs that mean the same Entry. Alsolai, H.; Roper, M. A systematic literature review of machine learning techniques for software maintainability prediction. It contains well written, well thought and well explained computer science and programming articles, quizzes and practice/competitive programming/company interview Questions. One of the theoretical implications of this study that could be further exploited in software-engineering-related research is the insight into the characteristics of the evaluated variants when applied in different contexts, which was gained through the empirical evaluation and comparison of different variants of the Index. Objects are identical when they share the class identity. = kurtosis, SW = ShapiroWilk Test. This resulted in several defined variants of the Index. Although different variants presented different values when subjected to the same software, their values were strongly positively correlated and generally indicated similarly how maintainability evolved between releases and over the long term. The Maintainability Index is commonly used as a quantitative measure of the relative ease of software maintenance. In Proceedings of the 2012 ACM-IEEE International Symposium on Empirical Software Engineering and Measurement, Lund, Sweden, 1920 September 2012; pp. Maintainab. ; Ojha, A. The comparison operator == tests whether two reference variables point to the same object. After that, in the first println statement, we have invoked equals() method and parse an object y as a parameter that compares the object x and y. Although numerous measures have been proposed in the literature for assessing software quality factors, few studies have focused on comparing the Index with other maintainability or software quality measures. Available online: Molnar, A.J. Naturally, it is to be expected that maintainability assessment based on different variants computed using different equations may yield different results when subjected to the same software. In summary, the key contributions of this paper are: (1) a review of Maintainability Index variants utilized for maintainability measurement in object-oriented software; (2) an empirical investigation on how Maintainability Index variants perform when utilized for the maintainability measurement of a single object-oriented system; (3) an empirical investigation on how Maintainability Index variants perform when utilized for the maintainability measurement of an object-oriented software system in the context of other systems, i.e., other versions of the same software system and completely different software systems. ; visualization, T.H. Misra, S.C. For Published at DZone with permission of Dror Helper, DZone MVB. Available online: Stack Overflow. Please let us know what you think of our products and services. A systematic and comprehensive investigation of methods to build and evaluate fault prediction models. permission is required to reuse all or part of the article published by MDPI, including figures and tables. There are several Index variants that differ in the factors affecting maintainability (e.g., code complexity, software size, documentation) and their given importance.