IT Interview Questions

1. Design and implement a String class that satisfies the following:

• Supports embedded nulls
• Provide the following methods (at least)
  • Constructor
  • Destructor
  • Copy constructor
  • Assignment operator
  • Addition operator (concatenation)
  • Return character at location
  • Return substring at location
  • Find substring
• Provide versions of methods for String and for char* arguments

2. Given the following classes

class Fruit {
// …
}

class Apple : public Fruit {
// …
}

class Peach : public Fruit {
// …
}

Q: How do you link a C++ program to C functions?
A: By using the extern “C” linkage specification around the C function declarations.

Q: Explain the scope resolution operator.
A: It permits a program to reference an identifier in the global scope that has been hidden by another identifier with the same name in the local scope.

Q: What are the differences between a C++ struct and C++ class?
A: The default member and base-class access specifiers are different.

Q: How many ways are there to initialize an int with a constant?
A: Two.

Q: What is a virtual destructor?
A: The simple answer is that a virtual destructor is one that is declared with the virtual attribute.

Q: Explain the ISA and HASA class relationships. How would you implement each in a class design?
A: A specialized class “is” a specialization of another class and, therefore, has the ISA relationship with the other class. An Employee ISA Person. This relationship is best implemented with inheritance. Employee is derived from Person. A class may have an instance of another class. For example, an employee “has” a salary, therefore the Employee class has the HASA relationship with the Salary class. This relationship is best implemented by embedding an object of the Salary class in the Employee class.

What is a Make file?(Fujitsu)
Make file is a utility in Unix to help compile large programs. It helps by only compiling the portion of the program that has been change

What is deadlock? (Novell)
Deadlock is a situation when two or more processes prevent each other from running.Example: if T1 is holding x and waiting for y to be free and T2 holding y and waiting for x to be free deadlock happens.

What is semaphore? (Novell)
Semaphore is a special variable, it has two methods: up and down. Semaphore performs atomic operations, which means ones a semaphore is called it can not be inturrupted.

1. What is the output of printf(”%d”)
2. What will happen if I say delete this
3. Difference between “C structure” and “C++ structure”.
4. Diffrence between a “assignment operator” and a “copy constructor”
5. What is the difference between “overloading” and “overridding”?
6. Explain the need for “Virtual Destructor”.
7. Can we have “Virtual Constructors”?
8. What are the different types of polymorphism?
9. What are Virtual Functions? How to implement virtual functions in “C”
10. What are the different types of Storage classes?
11. What is Namespace?
12. What are the types of STL containers?.
13. Difference between “vector” and “array”?