The black box and white box testing are the type of testing methods, which can be differentiated according to the approaches used for testing. Black box testing does not contain any information about the internal structure of the software but the functional specifications of the software are used to design the test cases. Conversely, the white box testing needs entire information about the internal structure of the software to construct the test cases.
Software testing is the method of examining a software entity to distinguish the existing and desired conditions and to evaluate the characteristics of the software entity. In other words, testing is a very essential element of the software quality assurance where the correctness of the software code and functionality is checked.
Content: Black Box Testing Vs White Box Testing
|Basis for comparison||Black-box Testing||White-box Testing|
|Basic||It concentrates on the functional requirements of the software.||It focuses control structure of the procedural design.|
|Applicable to||Acceptance and system testing||Unit and integration testing|
|Programming knowledge||Not necessary||Essential to have the programming knowledge|
|Design and implementation knowledge||Not required||Required|
|Test case approach follows||Requirement specification||Detailed design|
|Objective||To check what functionality is performed by the system.||To check how the system is performing the particular function.|
|Applied to||A large part of the software.||Modules and the small group of modules.|
Definition of Black Box Testing
Black box testing emphasises the functional requirement of the software rather than internal requirements. It also derives test cases or set of input conditions with the intent of exercising all the functional requirements for a program. This type of testing does not require the tester to be programming language savvy. Implementation details are also not covered in the black box testing. , and the prior attention is given to the information domain.
The black box testing finds errors for the following cases.
- Invalid or missing functions.
- Interface errors.
- Data structure and external database access errors.
- Errors regarding behaviour and performance.
- Initiation and termination errors.
The test cases derived during the black box testing satisfy some conditions given below.
- The test case must be decreased by the amount greater than one.
- A test case should relate to the presence and absence of the categories of errors.
Definition of White Box Testing
White box testing is a testing strategy which utilises the control structure of the procedural design to design the test cases. Other names for white box testing are glass-box testing and structural testing. It is mainly used to check the software defects existing in the system. The white box tester must know the code, means that the programming and the implementation knowledge is essential for the white box testing. It is performed in the early stages of the testing process, unlike black box testing. Linearly independent tests are derived using program graphs.
The White box testing emphasizes the following elements :
- Whether the independent paths in a module have been verified at least once or not.
- The logical decisions must be checked for both the sides true as well as the false side.
- All the loops must be executed at their boundaries in the operational bounds.
- The internal data structures are exercised for their validation.
Key Differences Between Black Box and White Box Testing
- The emphasis is on the functional requirement of the software in the black box testing. On the contrary, white box testing focuses on the control structure and procedural design.
- Acceptance and system testing are some types of techniques come under black box testing. As against, the techniques performed under the white box testing are the unit and integration testing.
- For performing white box testing, the tester must know design, code, and its implementation. On the other hand, in black box testing, this is not required.
- The analysis of the requirement specification is the foundation of the black box testing. In contrast, the white box testing examines the design in detail before performing the test.
- The aim of performing the black box testing is to check the functionality of the system. Conversely, the white box testing is conducted to examine the performance of the system while executing any function.
- Black box testing is applied to the large programs while small program components undergo white box testing.
The black box testing concentrates on the finished product and the process utilised to obtain the outcome. On the other hand, the white box testing focuses on the minor details and internal functioning of the system.