Sap Labs Interview Question for Software Engineer / Developers


Country: India
Interview Type: In-Person




Comment hidden because of low score. Click to expand.
1
of 1 vote

compiler creates an object in which the first offset is a virtual pointer.
the virtual pointer points to a vtable that holds a list of function addresses.
given an object pointer, you can compute the location at which the vtable lies and hence the address of each virtual function.
how is this useful ?

Suppose I write implementation for an object,I can supply only the vtable (aka interface) to a customer and advertise only the virtual functions in my object.
The customer barely knows any other functions that are present in the object.
But has everything to call virtual functions in that object(address & signature)

Apologize for lengthy rhetoric:(

- fountainh October 16, 2011 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 votes

Some languages (I'm gathering this was probably a C++ question) also have functions that are non-virtual, in which case they wouldn't be included in the vtable.

- eugene.yarovoi October 16, 2011 | Flag


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