Final Terms to Know Flashcards
Study these terms before the final for COMS W1004: Introduction to Computer Science and Programming in Java
accessor method
a method that accesses an object but does not change it
ACK
in data networking, an acknowledgement (or acknowledgment) is a signal passed between communicating processes or computers to signify acknowledgement, or receipt of response, as part of a communications protocol
actual parameter
Formal parameters are the parameters as they are known in the function definition. Actual parameters (also known as arguments) are what are passed by the caller.
address
the code that identifies where a piece of information is stored
algorithm
an unambiguous, executable, and terminating specification of a way to solve a problem
API
(Application Programming Interface) a code library for building programs
argument
a value supplied in a method call, or one of the values combined by an operator
arithmetic/Logic Unit (ALU)
a digital circuit that performs integer arithmetic and logical operations
ARQ Algorithm
Automatic Repeat reQuest (ARQ), also known as Automatic Repeat Query, is an error-control method for data transmission that uses acknowledgements (messages sent by the receiver indicating that it has correctly received a data frame or packet) and timeouts (specified periods of time allowed to elapse before an acknowledgment is to be received) to achieve reliable data transmission over an unreliable service. If the sender does not receive an acknowledgment before the timeout, it usually re-transmits the frame/packet until the sender receives an acknowledgment or exceeds a predefined number of re-transmissions
ASCII
the American Standard Code for Information Interchange is a character-encoding scheme originally based on the English alphabet that encodes 128 specified characters - the numbers 0-9, the letters a-z and A-Z, some basic punctuation symbols, some control codes that originated with Teletype machines, and a blank space - into the 7-bit binary integers
assembly language
an assembly language is a low-level programming language for a computer, or other programmable device, in which there is a very strong (generally one-to-one) correspondence between the language and the architecture’s machine code instructions
binary
number system, also known as base-2, that represents numeric values using two symbols: typically 0 and 1
bit
binary digit; the smallest unit of information, having two possible values: 0 and 1. A data element consisting of n bits has 2^n possible values.
boolean
a type with two possible values: true and false
boolean expression
an expression in a programming language that produces a Boolean value when evaluated, i.e. one of true or false
boolean operator
an operator that can be applied to Boolean values. Java has three Boolean operators: &&, ||, and !
byte
a number made up of eight bits. Essentially all currently manufactured computers use a byte as the smallest unit of storage in memory.
bytecode
instructions for the Java virtual machine
cache memory
random access memory (RAM) that a computer microprocessor can access more quickly than it can access regular RAM
cast
explicitly converting a value from one type to a different type. For example, the cast from a floating-point number x to an integer is expressed in Java by the cast notation (int) x.
Church-Turing Thesis
in computability theory, the Church–Turing thesis (also known as the Turing–Church thesis,[1] the Church–Turing conjecture, Church’s thesis, Church’s conjecture, and Turing’s thesis) is a combined hypothesis (“thesis”) about the nature of functions whose values are effectively calculable; or, in more modern terms, functions whose values are algorithmically computable. In simple terms, the Church–Turing thesis states that a function is algorithmically computable if and only if it is computable by a Turing machine
class
a programmer-defined data type
compiler
a program that translates code in a high-level language (such as Java) to machine instructions (such as bytecode for the Java virtual machine)
computability
computability is the ability to solve a problem in an effective manner. It is a key topic of the field of computability theory within mathematical logic and the theory of computation within computer science. The computability of a problem is closely linked to the existence of an algorithm to solve the problem.
computer network
a computer network or data network is a telecommunications network that allows computers to exchange data. In computer networks, networked computing devices pass data to each other along data connections. The connections (network links) between nodes are established using either cable media or wireless media. The best-known computer network is the Internet
computer science
the study of algorithms including their formal and mathematical properties, their hardware realizations, their linguistic realizations, and their applications
computing agent
any object capable of understanding and executing our instructions.
constructor
a sequence of statements for initializing a newly instantiated object
control unit
unit within the computer that actually carries out the operations of a program
DASD
in mainframe computers and some minicomputers, a direct access storage device, or DASD, is any secondary storage device which has relatively low access time relative to its capacity
DNS
the Domain Name System (DNS) is a hierarchical distributed naming system for computers, services, or any resource connected to the Internet or a private network
ethernet
Ethernet is a family of broadband computer networking technologies for local area networks (LANs). Ethernet was commercially introduced in 1980 and standardized in 1985 as IEEE 802.3. Ethernet has largely replaced competing wired LAN technologies such as token ring, FDDI, and ARCNET
encapsulation
the hiding of implementation details
explicit parameter
a parameter of a method other than the object on which the method is invoked
flops
floating-point operations per second
formal parameter
a variable in a method definition
gigabyte
2^30, or close to a billion, bytes
Halting Problem
in computability theory, the halting problem can be stated as follows: “Given a description of an arbitrary computer program, decide whether the program finishes running or continues to run forever”. This is equivalent to the problem of deciding, given a program and an input, whether the program will eventually halt when run with that input, or will run forever.
HTTP
(Hypertext Transfer Protocol) the protocol that defines communication between web browsers and web servers