University:
California State University, Northridge
Course:
COMP 333 | Concepts of Programming Languages
Academic year:

2023
Views:

381

Pages:

2
Author:

Samuel K

NYI NYI MOE HTET COMP 333 ASSIGNMENT 6 1. VAX minicomputers use a format for floating-point numbers that is not the same as the IEEE standard. What is this format, and why was it chosen by the designers of the VAX computers? A reference for VAX floating-point representations is Sebesta (1991). The existing DEC VAX formats, inherited from the PDP-11, because the PDP-11 had several uniquely innovative features, and was easier to program than its predecessors through the additional general-purpose registers. 2. Explain all of the differences between Ada’s subtypes and derived types. Subtypes are a way of refining an existing type by restricting the range of values that the type can represent, while derived types are a way of creating new types from existing types. Subtypes are compatible with their base type, while derived types are not. Subtypes inherit the operations of their base type, while derived types can inherit from their base type or define their own. Subtypes are used to refine existing types, while derived types are used to create new types. 3. What are all of the differences between the enumeration types of C++ and those of Java? C++ enums are integer constants that can be used in arithmetic expressions and implicitly converted to integers. Java enums, on the other hand, are first-class objects with their own type, offering stronger typing, and allowing for methods, fields, and constructors within the enum definition. Java enums also support interfaces and implicitly extend the Enum class, providing a degree of inheritance. 4. Multidimensional arrays can be stored in row major order, as in C++, or in column major order, as in Fortran. Develop the access functions for both of these arrangements for threedimensional arrays. Let the subscript ranges of the three dimensions be named min(1), min(2), min(3), max(1), max(2), and max(3). Let the sizes of the subscript ranges be size(1), size(2), and size(3). Row Major Order: location(a[i,j,k]) = (address of a[min(1),min(2),min(3)]) + ((i-min(1))*size(3) + (j-min(2)))*size(2) + (k-min(3)) Column Major Order: location(a[i,j,k]) = (address of a[min(1),min(2),min(3)]) + ((k-min(3))*size(1) + (j-min(2)))*size(2) + (i-min(1)) 5. In the Burroughs Extended ALGOL language, matrices are stored as a single-dimensioned array of pointers to the rows of the matrix, which are treated as single-dimensioned arrays of values. What are the advantages and disadvantages of such a scheme? The scheme of storing matrices as a single-dimensional array of pointers to rows allows fast access to elements in the order of rows, as obtaining the pointer to a row enables quick retrieval of all its elements. However, accessing matrix elements in column order is comparatively slower due to the need for fetching a row pointer and additional address computation for each access. It was designed for virtual memory environments to accommodate large multidimensional arrays that exceed the physical memory capacity of a computer.