C++ Interview Questions Part 2

C++ interview question :what is the difference betwen wait() and delay()?

Answer :Wait() and delay() works same but works on different platforms. Wait(2) will wait processing fro 2 second on Linux/Unix while delay(2000) with wait for 2 second but on DOS or Windows. so wait(2) on linux == delay(2000) on DOS Delay() is under while one can directly use wait in his/her program. 

C++ interview question :Why always array starts with index 0

Answer :Array name is a constant pointer pointing to the base address(address of the first byte where the array begin) of the memory allocated. When you use arr[i], the compiler manipulates it as *(arr + i). Since arr is the address of the first element, the value of i must be 0 for accessing it. Hence all arrays begin with an index of 0. 

C++ interview question: Can main() be overridden 

Answer : In any application, there can be only one main function. In c++, main is not a member of any class. There is no chance of overriding 

C++ interview question :What is the difference between macro and inline()? 

Answer :

1. Inline follows strict parameter type checking, macros do not.

2. Macros are always expanded by preprocessor, whereas compiler may or may not replace the inline definitions. 

C++ interview question: How can double dimensional arrays be dynamically initialized in C++?

Answer :example of how to dynamically initialize double dimensional arrays:

int num[2][3] = {34,32,30,24,22,20};

num[1][1] = 34

num[1][2] = 32

num[1][3] = 30

num[2][1] = 24

num[2][2] = 22

num[2][3] = 20 

C++ interview question: Can destructor be private?

Answer: Yes destructors can be private. But according to Standard Programming practice it is not advisable to have destructors to be private.