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A basic example is in the argv argument to the main function in C (and C++), which is given in the prototype as char **argv—this is because the variable argv itself is a pointer to an array of strings (an array of arrays), so *argv is a pointer to the 0th string (by convention the name of the program), and **argv is the 0th character of the ...
C++ supports multiple inheritance of arbitrary classes. In Java a class can derive from only one class, [1] but a class can implement multiple interfaces [17] (in other words, it supports multiple inheritance of types, but only single inheritance of implementation). Java explicitly distinguishes between interfaces and classes.
C appears to support assignment of array pointers, but in fact these are simply pointers to the array's first element, and again do not carry the array's size. [citation needed] In most languages, data types are not first-class objects, though in some object-oriented languages, classes are first-class objects and are instances of metaclasses.
In computer science, pointer analysis, or points-to analysis, is a static code analysis technique that establishes which pointers, or heap references, can point to which variables, or storage locations. It is often a component of more complex analyses such as escape analysis. A closely related technique is shape analysis.
For example, in the Pascal programming language, the declaration type MyTable = array [1..4,1..2] of integer, defines a new array data type called MyTable. The declaration var A: MyTable then defines a variable A of that type, which is an aggregate of eight elements, each being an integer variable identified by two indices.
Note: Java does not support pointers. [6] It is because pointers (with restrictions) are the default way of accessing objects in Java, and Java does not use stars to indicate them. For example, i in the last example is a pointer and can be used to access the instance. One can also declare a pointer to "read-only" data in C++.
In C++, classes can be forward-declared if you only need to use the pointer-to-that-class type (since all object pointers are the same size, and this is what the compiler cares about). This is especially useful inside class definitions, e.g. if a class contains a member that is a pointer (or a reference) to another class.
The implicit copy constructor of a class calls base copy constructors and copies its members by means appropriate to their type. If it is a class type, the copy constructor is called. If it is a scalar type, the built-in assignment operator is used. Finally, if it is an array, each element is copied in the manner appropriate to its type. [3]