DDE (Dynamic Data Exchange) a communication protocol that let applications call each other.

OLE was the first protocol that enabled users and programmers to create compound documents?that is documents that contain data from different applications (for example an Excel worksheet inside a Word document).

- When u build connection with database through coding, then its ADODB.When u build connection with database through ADO component, then its ADODC.

- ADODB is a ActiveXdll and ADODC is a ActiveXcontrol.

- No Need to bind with controls in ADODB whereas in ADODC we should bind with controls.

Tree view control is designed to display data that is hierarchical in nature, such as organization trees, the entries in an index, the files, directories on a disk. It is often used in conjuction with the List view control, which is used to display the contents of the folder selected in the tree view.

List view control displays data as listitem objects. The control excels at representing subsets of data or discrete objects.The list view property is often used in association with a tree view control.

COM is the component Object Model is a system whch creates application which are binary form that is language independent , object oriented ,modular and reusable .

IUnknown as an interface of a COM object. Every COM object has to support IUnknown, besides optionally adding other interfaces.

IUnknown is made of QueryInterface, AddRef and Release.

An in-stream PROC is defined right in the jcl stream and doesn't reside in the proclib. This is an older technique associated with punched cards but it is still in use with setup and installation programs from vendors.

for the in-line perform instead of:

perform add-paragraph until switch = 'y'

you can code

perform until switch = 'y'

body of code

end-perform

body of code is the code from add-paragraph appearing in-line (ie right in the perform) instead of in a separate paragraph (out of line code)

If in application program IO-PCB is there then it is a online program. In ENTRY statement IO-PCB must be listed first and then DB-PCB.

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