Question-71. Which key word is used to perform unconditional branching ?
Answer- goto.
Question-72. What is the purpose of #undef preprocessor ?
Answer- It will be used to undefine an existing macro definition.
Question-73. What is virtual destructor ?
Answer- A virtual destructor ensures that the objects resources are released in the reverse order of the object being constructed w.r.t inherited object.
Question-74. What is the order of objects destroyed in the memory ?
Answer- The objects are destroyed in the reverse order of their creation.
Question-75. What is a friend class ?
Answer- A class members can gain accessibility over other class member by placing the class declaration prefixed with the keyword ‘friend’ in the destination class.
Question-76. What is C++ ?
Answer- C++ is an object oriented programming language created by Bjarne Stroustrup. It is released in 1985.
Question-77. What are the advantages of C++ ?
Answer- C++ doesn’t only maintains all aspects from C language, it also simplify memory management and add several features like:
Includes a new datatype known as a class. Allows object oriented programming.
Question-78. What is the difference between C and C++ ?
Answer-
| C | C++ |
|---|---|
| 1) C follows the procedural style programming. | 1) C++ is multi-paradigm. It supports both procedural and object oriented. |
| 2) Data is less secured in C. | 2) In C++, you can use modifiers for class members to make it inaccessible for outside users. |
| 3) C follows the top-down approach. | 3) C++ follows the bottom-up approach. |
| 4) C does not support function overloading. | 4) C++ supports function overloading. |
| 5) In C, you can’t use functions in structure. | 5) In C++, you can use functions in structure. |
| 6) C does not support reference variables. | C++ supports reference variables. |
| 7) In C, scanf() and printf() are mainly used for input/output. | 7) C++ mainly uses stream cin and cout to perform input and output operations. |
Question-79. What is the difference between reference and pointer ?
Answer-
| Reference | Pointer |
|---|---|
| 1) References are less powerful than pointers. Once a reference is created, it can’t refer to other object later. | 1) Pointers provide the powerful facilities than references. |
| 2) References are safer and easier to use than pointers. | 2) Pointers are comparatively difficult to use. |
Question-80. What is the first string in the argument vector w.r.t command line arguments ?
Answer- Program name.