Reference Variable in C++
Reference Variables. C++ added the so-called reference variables (or references in short). A reference is an alias or an alternate name to an existing variable. For example, suppose you make peter a reference (alias) to paul, you can refer to the person as either peter or paul.
A reference variable is a variable that points to an object of a given class, letting you access the value of an object. For example, you can retrieve a row from a database table and assign all values from the row to a single object and then pass the object to a called procedure.
References are often confused with pointers but three major differences between references and pointers are:
- You cannot have NULL references. You must always be able to assume that a reference is connected to a legitimate piece of storage.
- Once a reference is initialized to an object, it cannot be changed to refer to another object.
- Pointers can be pointed to another object at any time.
- A reference must be initialized when it is created. Pointers can be initialized at any time.
A reference variable is a variable that points to an object of a given class, letting you access the value of an object. An object is a compound data structure that holds values that you can manipulate. A reference variable does not store its own values. Instead, when you reference the reference variable, OpenROAD uses the values in the corresponding object. The object is made up of attributes, which can be simple variables, reference variables, or array variables.
The class of an object defines its attributes. OpenROAD includes both system classes and user-defined classes.
In your 4GL code, when you reference a reference variable, you can work with the entire object as a single unit. For example, you can retrieve a row from a database table and assign all values from the row to a single object and then pass the object to a called procedure. You can also work with the individual attributes in the object.
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