As we all know that in white box testing we have the access 
to the code so in white box testing we can look at the code 
before deciding the test data and also we can know the 
potential area where the bugs can be found by looking at 
the code

White Box Testing requires that the test engg has knowledge
abt the program structure/Coding,the code design is exposed
to the test engg whereas in 
Black Box Testing the test engg does not require the
knowledge abt the program structure,the code is hiddden from
the test engg.His job is to test the functionality of the
system.

White Box Testing requires that the test engg has knowledge
abt the program structure/Coding,the code design is exposed
to the test engg whereas in 
Black Box Testing the test engg does not require the
knowledge abt the program structure,the code is hiddden from
the test engg.His job is to test the functionality of the
system.

white box testing is Testing of a function with knowing 
internal structure of the program. (Developing stage)

Black Box testing is Testing of a function without knowing 
internal structure of the program. (Testing stage)

WHITE BOX testing done by the developer
White box is nothing but coding.
White box testing is also called as glass box testing.
In these testing entire code of the system must be 
available.
It is design based testing.
It is a structural testing.
In this white box testing developer must know the 
structural knowledge.
In this white box testing some of these aspects will be 
considered.
All indepent parts are executed at least once.
All logical dession are exercised both true are false.
All loops are executed at there boundaries.
All internal data structure will be exercised.

ADVANTAGES= 1. COVER common Ares.
2. Cover control structure.
3. Test an integrated the many modules.
For white box testing the developers must know the 
structural knowledge. It focuses on the program part rather 
then the funcnalitypart.

While doing a black box testing we will know the 
requirement and we directly test the functionality. Here 
there is a possibility of leaving certain input condition
(practically speaking exhaustive testing of the system is 
not at all possible) which may lead to erroneous result. 
This situation described above can be completely avoided by 
doing an whitebox testing where we will have the access to 
code and bring up a test scenario where the system will 
fail and expose the hidden defect.

whitebox testing is done by the developers and it is used 
to do unit and integration testing only. in blackbox 
testing u do functional testing,usability testing and    
non-functinality testing