Section 1
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What were two major differences between third-generation programming languages and previous generations?
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Section 1
(50 cards)
What were two major differences between third-generation programming languages and previous generations?
primitives were both higher level and machine independent
Why were these translators called compilers?
had to compile several machine instructions into short sequences to simulate the activity requested by a single high-level primitive
What does FORTRAN stand for?
FORmula TRANslator
What does COBOL stand for?
COmmon Business Oriented Language
How do primitives used in assembly language compare with those used in machine language?
essentially the same with only difference being the syntax used to represent them
How is a program constructed under the functional paradigm?
by connecting smaller predefined program units so that each unit's outputs are used as another unit's inputs in such a way that the desired overall input-to-output relationship is obtained
What were created once a given mnemonic system was established?
programs called assemblers
What is the only way to transport a program written in assembly language to another computer design?
rewrite it to conform to the new computer's register configuration and instruction set
What was COBOL developed for?
business applications
What has the declarative approach been used for many years to do?
to simulate a system in order to test hypotheses or to obtain predictions
What does the term assembly language refer to?
a mnemonic system for representing programs
Why have informal standards evolved in some cases?
because of the popularity of a certain dialect of a language and the desire of other compiler writers to produce compatible products
What would be a more realistic term than "programming paradigms" for the different branches of programming languages?
software development paradigms
What is an example of an instruction in a mnemonic system to move the contents of register 5 to register 6?
MOV R5, R6
Why is "software development paradigm" a more realistic term than "programming paradigm"?
the paradigms represent fundamentally different approaches to building solutions to problems and therefore affect the entire software devleopment process
What does it mean to say that the primitives of third-generation programming languages were higher level?
they expressed instructions in larger increments
What were third-generation programming languages more conducive to?
software development
What are program variables?
descriptive names to refer to memory cells at discrete locations
What basic methodology does a declarative paradigm use?
a preestablished general-purpose problem-solving algorithm
What did translators theoretically allow?
use of a program written in a third-generation language on any machine simply by applying the appropriate compiler
How does the imperative paradigm define the programming process?
as the development of a sequence of commands that, when followed, manipulate the data to produce the desired result
How is the programming process defined under the functional paradigm?
building functions as nested complexes of simpler functions
What has the reality of compiler machine independence necessitated?
the implementation of at least minor modifications to a program to move it from one machine to another
What is another term for the imperative paradigm?
the procedural paradigm
What did assemblers save programmers from having to do?
from developing a program directly in machine language
How are high-level primitives dealt with once the design is complete?
can be translated to lower-level concepts relating to the details of implementation
How is a program viewed within the functional paradigm?
as an entity that accepts inputs and produces outputs
What is another term for program variable?
identifier
How does an interpreter run a program differently from a compiler?
rather than producing a machine-language copy of a program that would be executed later, an interpreter actually executes a program from its high-level form
What was the job of assemblers?
to convert mnemonic expressions into machine language instructions
What are programming paradigms?
alternative approaches to the programming process that have developed along different paths according to different sets of problem-solving priorities and methods
What is another disadvantage of an assembly language for how it forces the programmer to think?
a programmer, though not required to code instructions in numeric form, is still forced to think in terms of the small, incremental steps of the machine's language (doesn't allow for abstraction to larger scales of design)
What is a translator?
a program that translated programs expressed in high-level primitives into machine-language programs
What are language extensions?
features often provided by compiler designers that are not part of the standard version of the language
What was FORTRAN devleoped for?
scientific and engineering applications
What is the ideal adaptation of the design process?
the design process is better suited to the use of high-level primitives, each representing a concept associated with a major feature of the product
How did researchers simplify the (machine language) programming process in the 1940s?
by developing notational systems by which instructions could be represented in mnemonic rather than numeric form
What is the underlying algorithm in the simulation of systems?
the process of simulating the passage of time by repeatedly recomputing values of parameters based on the previously computed values
What does the term "second-generation languages" refer to?
assembly languages
What were the two best-known examples of third-generation programming languages?
FORTRAN and COBOL
What does the declarative paradigm emphasize in contrast to the imperative paradigm?
the problem to be solved rather than an algorithm to be followed
How is standardization of languages maintained?
the American National Standards Institute and the International Organization for Standardization have adopted and published standards for many of the popular languages
What is the reality of the theoretical machine independence of compilers?
when a compiler is designed, particular characteristics of the underlying machine are sometimes reflected as conditions on the language being translated
What is the result of the fact that assembly language primitives are the same as machine language primitives?
a program written in an assembly language is inherently machine dependent
Who developed COBOL?
the U.S. Navy
How do interpreters differ from compilers?
execute instructions as they are translated instead of recording the translated version for future use
What is an example of how differences in process handling from machine to machine have resulted in different dialects of a language?
the different ways in which machines handle I/O operations have historically caused the "same" language to have different characteristics, or dialects, on different machines
What emerged as an alternative to compilers for implementing third-generation languages?
interpreters
What does it mean to say a language is machine dependent?
the instructions within the program are expressed in terms of a particular machine's attributes (instructions not portable)
What does the term "first-generation languages" refer to?
machine languages
Section 2
(50 cards)
What does the term "instance" (of a class) refer to in the object-oriented paradigm?
an object that is based on a particular class
What are modern languages designed with in order to avoid the complexities that may arise from relying on goto statements?
control statements that allow an entire branching pattern to be expressed within a single lexical structure
What is a class in the object-oriented paradigm?
a description of the object's properties
What complications can the use of literals result in?
they can complicate the task of modifying the program should it become necessary (if the value in a literal changes, each reference to the value throughout the program must be located and changed)
What does the assignment statement do?
requests that the value of an expression be assigned to a variable (or more precisely, stored in the memory area identified by the variable)
What does structured programming consist of?
an organized design methodology combined with the appropriate use of the language's control statements
What are data types that have not yet become widespread primitives?
images, audio, video, and hypertext
What is data structure?
the conceptual shape or arrangement of data, with each type of data having a structure typical for that type
What are visual programming languages also called?
block-based programming languages
What is a local variable?
a variable that can be referenced only within that function
What does the goto statement provide?
a means of directing the execution sequence to another location that has been labeled for this purpose by a name or number (i.e., a direct application of the machine-level JUMP instruction)
How can the complications resulting from the use of literals be made even worse?
if the value contained in a literal is also used in reference to other quantities in a program, there is no way to know which occurrences to change and which to leave alone
What is an example of an aggregate type and the data it might contain?
a block of data referring to an employee might consist of an entry called Name of type character, an entry called Age of type integer, and an entry called SkillRating of type float
What is the implication of the way objects are constructed out of methods?
most object-oriented programming languages contain many of the features found in imperative languages
What value declaration can be used in place of a literal to solve potential problems created by use of literals?
constant
What is the simplest control statement?
the goto statement
What is a constant?
a descriptive name assigned to specific, nonchangeable values
What do many programming languages require to establish an array in a program?
that the declaration statement declaring the name of the array also specify the length of each dimension of the array
What term for functions is preferred in object-oriented languages when programmers specify how objects should respond to various stimuli?
method
What options does a programmer have for referring to an aggregate type once an aggregate has been declared?
a programmer can use the structure name to refer to the entire aggregate or can reference individual fields within the aggregate by means of the structure name followed by a period and the field name
What is control transferred during the execution of a function?
control is transferred to the function at the time its services are required and then returned to the original program unit after the function has finished
How does structured programming achieve its goal?
by restricting the use of those features that have historically led to sloppy programming while encouraging the use of better-designed features
What is the most basic kind of imperative statement?
the assignment statement
What are common primitive data types (or "primitives")?
integer, float, character, and Boolean
What does the term "calling unit" usually refer to?
a program unit that requests the execution of a function
What does a function's header do?
identifies the name of the function
What is a literal?
the explicit appearance in a program of a value
What can excessive use of goto statements result in?
needlessly convoluted code
How are literals consisting of text distinguished from other program components?
they are delineated with single or double quotation marks
What are some examples of block-based languages used in education?
Alice, Scratch, StarLogo, and App Inventor
What does the term "overloading" refer to?
the use of a single symbol to indicate more than one operation in different contexts
What does a control statement do?
alters the execution sequence of the program
How is a software system viewed in the object-oriented paradigm?
as a collection of units, called objects, each of which is capable of performing the actions that are immediately related to itself as well as requesting actions of other objects
What is the array?
a block of elements of the same type such as a one-dimensional list, a two-dimensional table with rows and columns, or tables with higher dimensions
What is one reason why the use of literals is not considered good programming practice?
they can mask the meaning of statements in which they appear
What follows the header in a function?
statements that define the function's details
What are visual programming languages?
an alternative to traditional text-based programming environments that allow the developer to manipulate graphical blocks on the screen to create programs
What are other terms for aggregate type?
structure, record, or heterogeneous array
What is the scope of a variable?
the portion of a program in which a variable can be referenced
What is a function?
a set of instructions for performing a task that can be used as an abstract tool by other program units
What are functions called in the object-oriented vernacular?
methods
What are indices?
integer values that identify an individual element in an array by specifying the row, column, and so on, desired
What does APL stand for?
A Programming Langauge
What is the nature of the methods within an object?
they are essentially small imperative program units
How is the entire system constructed in the object-oriented paradigm?
as a collection of objects, each of which knows how to respond to the events related to it
What is an aggregate type?
a block of data in which different elements can have different types
What do the terms "calling" or "invoking" the function refer to?
the process of transferring control to a function
primitive data types
the data types that are included in a programming language
What does structured programming encourage?
allowing algorithms to be expressed in a readable form while also assisting the programmer in obtaining such readability
What are global variables?
variables whose scopes are not restricted to a particular part of a program
Section 3
(50 cards)
What are syntax diagrams?
pictorial representations of a language's grammatical structure
What does the term "just-in-time compilation" refer to?
the quick translation of of software into universal machine language just prior to execution
How is "ambiguous grammar" defined?
a grammar that allows two distinct parse trees for one string
What is an object program?
the translated version of a program
What does passing a parameter by value entail?
a duplicate of the data represented by the actual parameters is produced and given to the function
What is a more efficient way than passing by value of dealing with parameters when they contain large blocks of data?
passing by reference
What three activities are performed by corresponding units in the translator?
lexical analysis, parsing, and code generation
What does the term "actual parameters" refer to?
the precise meanings assigned to the formal parameters when the function is applied
What does a type cast do?
notifies the compiler that the programmer is aware that a type conversion will be applied
What does a parse tree represent?
the parser's interpretation of the program's grammatical composition
What were fixed-format languages?
early programming languages that insisted that each program statement be positioned in a particular manner on the printed page
What is another term for a single entity as recognized by a lexical analyzer?
a token
What does "strongly typed" mean?
all activities requested by a program must involve data of agreeable types
What does passing by reference allow?
allows the function to modify the data residing in the calling environment
Under what condition will some languages, such as Java, allow coercion?
as long as it is a type promotion
Why is coercion frowned upon by many language designers?
it can alter the value of a data item, resulting in subtle program bugs
What is parsing?
the process of recognizing the grammatical structure of a program
What is a source program?
the program in its original form
In what cases is passing parameters by value inefficient?
when the parameters represent large blocks of data
What is one way of expressing the rules of grammar?
syntax diagrams
How does a lexical analyzer process tokens?
encodes each token with its classification and hands them to the parser
What relationship to coercion do most modern languages have?
most modern languages are strongly typed and thus do not allow coercion
What is code optimization?
implementation of shortcuts in the execution of a program by recognizing components within a program that have already been compiled
What is lexical analysis?
the process of recognizing which strings of symbols from the source program represent a single entity
What are nonterminals?
terms in a syntax diagram that require further description
What is a type promotion?
coercion that involves converting a low precision value to a higher precision value
What are free-format languages?
languages in which the positioning of statements is not critical
What are parameters?
generic terms within functions that are replaced by specific instantiations when the function is run
What benefits does passing a parameter by value provide?
protects the data in the calling unit from being mistakenly altered by a poorly designed function
What is code generation?
the process of constructing the machine-language instructions to implement the statements recognized by the parser
What are constructors?
special methods within a given class that handle specific initialization needs and are executed automatically when an object is constructed from the class
What is a grammar?
collective term for a set of rules that define the syntax of the programming language
What are methods in the object-oriented paradigm?
the functions within an object
What is coercion?
implicit conversion between types
How does passing by reference work?
gives the function direct access to the actual parameters by telling it the addresses of the actual parameters in the calling program unit
What are universal machine languages designed for?
to be quickly translatable
What does the process of parsing a program consist of?
constructing a parse tree for the source program
What are terminals?
terms in a syntax diagram that appear in ovals in the same form in which they appear in the program
What is a symbol table?
a table into which the parser records information being declared as it recognizes declarative statements
How is Python unusual in regard to the use of spacing?
it has aspects of free-format languages, but strictly requires indentation to mark structure, rather than punctuation marks like semicolons and curly braces
What is universal machine language called in Java?
bytecode
What are methods called in the C++ vernacular?
member functions
What is an instance variable?
a variable that resides within an object
What is translation?
the process of converting a program from one language to another
What are event-driven systems?
software systems in which functions are activated by events rather than explicit requests
How are grammatical ambiguities avoided in Python?
with indentation
What is a parse tree?
representation in pictorial form of the manner in which a particular string conforms to a set of syntax diagrams
What problem was solved by Sun Microsystems and Microsoft with the design of "universal machine languages"?
transferring software over the Internet for execution and, as a result, having to either suffer delays due to translation or provide a different version of the machine-language form of the software
What is another term for parameters?
formal parameters
What is universal machine language called in C#?
.NET Common Intermediate Language
Section 4
(20 cards)