Skip to main content

Black Box Vs White Box Testing

By

Black Box Testing also known as Behavioral testing is a software testing technique whereby the internal workings of the item being tested are not known by the tester.

For example, when black box testing is applied to software engineering, the tester would only know the "legal" inputs and what the expected outputs should be, but not how the program actually arrives at those outputs. It is because of this that black box testing can be considered testing with respect to the specifications, no other knowledge of the program is necessary

For example, in a black box test on software design the tester only knows the inputs and what the expected outcomes should be and not how the program arrives at those outputs. The tester does not ever examine the programming code and does not need any further knowledge of the program other than its specifications.

Black Box testing attempts to find errors in the following categories: -

  • Incorrect or missing functions.
  • Interface errors.
  • Errors in data structures or external database access.
  • Behavior or performance errors.
  • Initialization and termination errors.

The advantages of this type of Testing include:

  • The test is unbiased because the designer and the tester are independent of each other.
  • The tester does not need knowledge of any specific programming languages.
  • The test is done from the point of view of the user, not the designer.
  • Test cases can be designed as soon as the specifications are complete.
  • More effective on larger units of code than glass box testing
  • Tester needs no knowledge of implementation, including specific programming languages
  • Tester and programmer are independent of each other
  • Tests are done from a user's point of view
  • Will help to expose any ambiguities or inconsistencies in the specifications
  • Test cases can be designed as soon as the specifications are complete

The disadvantages of this type of testing include:

  • The test can be redundant if the software designer has already run a test case.
  • The test cases are difficult to design.
  • Testing every possible input stream is unrealistic because it would take a inordinate amount of time; therefore, many program paths will go untested.
  • Only a small number of possible inputs can actually be tested, to test every possible input stream would take nearly forever
  • Without clear and concise specifications, test cases are hard to design
  • There may be unnecessary repetition of test inputs if the tester is not informed of test cases the programmer has already tried
  • May leave many program paths untested
  • Cannot be directed toward specific segments of code which may be very complex (and therefore more error prone)
  • Most testing related research has been directed toward glass box testing
Labels:

Comments

Post a Comment

Popular posts from this blog

Convert JSON to XML using QTP/UFT/VBScript

By
Sample Code : Dim strPage,strJSON,objIE strPage = "C:\Jay\JLoader.html" Set objIE = CreateObject("InternetExplorer.Application") objIE.Visible = True objIE.Navigate2 strPage While objIE.Busy : Wend strJSON = "{""FirstName"":""Jay"", ""LastName"":""Krishna""}" Set objWin = objIE.document.parentWindow objWin.execScript "var jsonStr2XML = function(strJSON) { return json2xml(JSON.parse(strJSON));};" Msgbox  oWin.jsonStr2XML(strJSON) objIE.Quit In Detail: Converting The most popular data interchange format JSON(JavaScript Object Notation) to XML using QTP/UFT. Parsing JSON in UFT could be a challenge so we will use JavaScript in UFT to make it perfect. SO We need :              Java Script API  - To Convert JSON to XML                         JavaScript Files :                         http://goessner.net/download/prj/jsonxml/j
Post a Comment
Read more

Read Outlook mail attachment and Body using Vb Script or QTP

By
Set olApp = CreateObject("Outlook.Application") Set olns = olApp.GetNameSpace("MAPI") Set ObjFolder = olns.GetDefaultFolder(6) j = 0 For each item1 in ObjFolder.Items        iattachCnt = item1.Attachments.Count     Print "Attachments Count: " & iattachCnt     For i = 1 to iattachCnt         Print "FileName :    " & item1.Attachments(i).FileName         Print "Display Name:   " & item1.Attachments(i).DisplayName         Print "Size: " & item1.Attachments(i).Size     Next     Print " Body : " & item1.body     Print "--------------------------------------Mail Num - " & j & " -----------------------------------------------"     j = j+1    Next
Post a Comment
Read more

Excel Sorting By Rows and Columns

By
Excel Sorting By Row: Const xlAscending = 1 Const xlNo = 2 Const xlSortRows = 2 Set objExcel = CreateObject(“Excel.Application”) objExcel.Visible = True Set objWorkbook = objExcel.Workbooks.Open(“C:\Jay\Docs1.xls”) Set objWorksheet = objWorkbook.Worksheets(1) objWorksheet.Cells(1,1).activate Set objRange = objExcel.ActiveCell.EntireRow objRange.Sort objRange, xlAscending, , , , , , xlNo, , , xlSortRows set objExcel=nothing Excel Sorting By Column : Const xlAscending = 1′represents the sorting type 1 for Ascending 2 for Desc Const xlYes = 1 Set objExcel = CreateObject(“Excel.Application”)’Create the excel object objExcel.Visible = True’Make excel visible Set objWorkbook = _ objExcel.Workbooks.Open(“C:\Jay\Docs1.xls”)’Open the document Set objWorksheet = objWorkbook.Worksheets(1)’select the sheet based on the index .. 1,2 ,3 … Set objRange = objWorksheet.UsedRange’which select the range of the cells has some data other than blank Set objRange2 = objExcel.Range
Post a Comment
Read more

How to Read or Select Context Menu or Right Click Menu using QTP.

By
Select The Item in Right Click Menu or Context Menu: Window("sampleWindow").WinMenu("MenuObjType:=1).Select"File;New" Here MenuObjtype can be 1 r 2 r 3 .......n Check wether the Item is Exist or Not: If Window("sampleWindow").WinMenu("MenuObjType:=1).GetItemProperty("1","Exist") Then   Msgbox"Exist" Else  Msgbox"Does Not Exist" End If                                         Or If Window("sampleWindow").WinMenu("MenuObjType:=1).GetItemProperty("File","Exist") Then   Msgbox"Exist" Else  Msgbox"Does Not Exist" End If Get the Items in Context Menu: For i = 1 to 10 Print  Window("sampleWindow").WinMenu("MenuObjType:=" & i).GetItemProperty("1","Label") Then Next
Post a Comment
Read more

How to Download a file using VbScript

By
Following is the code to download a file using Vbscript, without using QTP This code uses the HTMLDom and URLDownloadToFile method from urlmon API. Since VBScript does support calling Native API methods directly, here I am using  Excel macro to declare a function for the urlmon API and running the macro by Excel API from VBscript Step1: Create a new excel and open the visual basic editor, Insert Module and paste the following code the Module, save the excel file Private Declare Function URLDownloadToFile Lib “urlmon” Alias _                                            “URLDownloadToFileA” ( _                                            ByVal pCaller As Long, ByVal szURL As String, _                                            ByVal szFileName As String, _                                            ByVal dwReserved As Long, _                                            ByVal lpfnCB As Long) As Long Sub FileSave(strUrl, Des)     r = URLDownloadToFile(0, strUrl, Des, 0, a)
Post a Comment
Read more