Whit box testing or glass box testing or structured based technique

We should know what is the processing inside. Its requires knowledge of the language being used inside the application.

Example:

 

Calculator- If we are not get the correct result as per the input, we need to know how those calcluation are don and fix the problem you can find. people dont know anything about the programming cannot do the white box testing.

if we find the issue in blackbox testing, this is not necessary look into the coding. we should performing the white box testing.

Defined by ISTQB

Structure-based testing techniques (which are also dynamic rather than static) use the internal structure of the software to derive test cases. They are commonly called 'white-box' or 'glass-box' techniques (implying you can see into the system) since they require knowledge of how the software is implemented, that is, how it works.

 For example, a structural technique may be concerned with exercising loops in the software. Different test cases may be derived to exercise the loop once, twice, and many times. This may be done regardless of the functionality of the software

How to test the white box testing

1) Guarantee that all independent paths within a module have been exercised at least once.
2) Exercise all logical decisions on their true and false sides.
3) Execute all loops at their boundaries and within their operational bounds
4) Exercise internal data structures to assure their validity.

We are using below concept of coverage for structured based technique or white box  testing.

-> code coverage
-> decision coverage
-> statement coverage,
-> structural testing
-> structure-based testing
-> white-box testing