Technology Questions

ARC is a compiler-level feature that simplifies the process of managing the lifetimes of Objective-C objects. Instead of you having to remember when to retain or release an object, ARC evaluates the lifetime requirements of your objects and automatically inserts the appropriate method calls at compile time.

A static method cannot access non static variables or methods because static methods doesnt need the object to be accessed. So if a static method has non static variables or non static methods which has instantiated variables they will no be intialized since the object is not created and this could result in an error.

In C++, void represents the absence of type, so void pointers are pointers that point to a value that has no type. The void pointers can point to any data type.

You can declare void pointer as follows:

void *p;

Wrapper classes wrap primitive values in a class and offers utility to access them through objects. Some of the primitive wrapper data types are:

Byte, short, int, long, float, double, char, Boolean.

Example: 

Create a class name VectorAdd to populate it with integer values using the add(int, object) method.

public class VectorAdd

{

       public static void main(String argv[])

       {

             Vector v = new Vector();

             v.add(0,new Integer(10));

             v.add(1,new Integer(20));

             v.add(2,new Integer(30));

             for(int i=0; i < v.size();i ++)

             {

                  Integer iw =(Integer) v.get(i);

                  System.out.println(iw);

             }

       }

}

Direct method,

 Subtraction method,

 Modulo-Division method,

 Digit-Extraction method,

 Mid-Square method,

 Folding method,

Pseudo-random method

A DB2 bind is a process that builds an access path to DB2 tables. 

WATER MARK is a divided segment of used and free blocks. Blocks which are below high WATER MARK i.e. used blocks, have at least once contained some data. This data might have been deleted later. Oracle knows that blocks beyond high WATER MARK don’t have data; it only reads blocks up to the high WATER MARK during a full table scan. 

Access specifiers in C++ determines the scope of the class members.

Public: If a class member is public, it can be used anywhere without the access restrictions.

Private: if a class member is private, it can be used only by the members and friends of class.

Protected: If a class member is protected, it can be used only by the members and friends of class and the members and friends of classes derived from class.