ISRO CSE 2016 | Question: 79

Question

Which one of the following is correct about the statements given below?

1. All function calls are resolved at compile time in C lang
2. All function calls are resolved at compile time in C++ lang

• A. Only II is correct
• B. Both I and II are correct
• C. Only I is correct
• D. Both I and II are incorrect

Comments

option B ?

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no,option(c) should be the answer here.

Answer 1

Consider here:

int (*p) ();
scanf("%d", &a);
if(a)
    p = fun1;
else
    p = fun2;
int b = (*p)();

This is an example of run time resolution of function calls in C. This is also applicable for C++ though it has other dynamic resolution via virtual functions. So, answer should be D. 

Comments

The example you gave here, sir, is of function pointer actually. Both of them are resolved during linking time only. It is the matter of determining the address of which function to be called, which is being done here.

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Without getting the address what is resolved at link time?

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The functions are getting resolved at link time just like every other functions do, sir. Importantly, what this if-else statement is doing is determining the address to which the control flow needs to be transferred when the function is called. If you want, you can stretch the definition of polymorphism and include this in it and call it static polymorphism, as this example here has an interface to call the functions instead of letting compiler decide it.

Answer 2

(1) C supports only "Early Binding" in which all the functions related to their function calls are resolved at compile time.

(2)C++ Supports both "Early Binding" and "Late Binding".Late Binding is the process of resolving functions related to function calls during Run time.

In C++ virtual calling mechanisms are resolved at run-time.

Hence,Option(c)only 1 correct.