CS exam 2
Terms
undefined, object
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- Abstraction
- the concept of hiding details. Can help control complexity and focus attention on appropriate issues
- accessor method
- code that is exclusively associeted with a class or with an object.
- actual parameter
- the value passed to a method as a parameter
- ALU
- arithmetic logic unit. subsystem that performs such mathematical and logical operations as addition, sutraction, comparison for equality.
- argument
- variable passed to method when it is invoked
- arithmetic operator
- an operator that performs a basic arithmetic computation, such as addition/multiplication
- array
- a programming language construct used to store an ordered list of primitive values or objects.
- assignment
- sets or resets a value assigned to a variable
- assembly language
- a low-level language that uses mneomonics to represent program commands
- binary
- the base-2 number system. modern computer systems store info as strings of binary digits (bits)
- bit
- a binary digit, either 0 or 1
- block
- a group of programming statements and declarations delimited by braces {}
- boolean
- a Java reserved word representing a logical data type that can only take the values true or false.
- boolean expression
- an expression that evaluates to a true or false result, primarily used as conditions in slection and repetition statements
- boolean operator
- any of the bitwise operaters AND OR or NOR when applied to boolean operands.
- byte
- a unti of binary stores equal to 8 bits
- bytecode
- low-level format into which the java compiler translates Java source code. interpreted and executed by the Java interpreter
- cache
- a memory area where frequently accessed data can be stored for rapid access.
- cast
- a java operation expressed using a type or class name in parantheses to eplicity convert and return a vlue of one data type into another.
- central processing unit (CPU)
- the hardware component that controls the main activity of a computer, including the flow of information and the execution of commands.
- class
- the blueprint of an object the model that defines the variables and methods an object will contain when instantiated
- class library
- a set of classes that define useful services for a programmer
- class method
- static method - invoked thru class name, cannot reference instance variables
- class variable
- a variable shared among all instane of a class. only one copy for all objects of the class (like count)
- compiler
- a program that translates code from one language to equivalent code in another language. The Java compiler translates java source code into java bytecode (interpreter)
- computer science
- study of algorithms including their formal/mathematical properties, hardware realizations, and applications
- control unit
- coordinates the processing steps - controls the interaction between a computer sstem and a particular kind of peripheral
- constructor
- a special method in a class that is invoked when an object is instantied form a class. used to initialize the object
- data type
- a designation hat speifies a set of values. each variable has a data type that specifies the kinds of values that can be stored in it.
- encapsulation
- the characteristic of an object that limits access to the variables and methods contained in it.
- file
- a named collection of data stored on a secondary storage device such as a disk.
- flops
- floating pt operations per second. measure of a computer's performane (number crunching)
- formal parameter
- an identifier (dummy variable) that serves as a parameter name in a method. It receives its initial value from the actual parameter passed to it.
- high level language
- a programming language in which each statements represents many machine-level instructions
- HTML
- Hypertext Markup Language. The notation used to define Web pages
- immutable
- the characteristic of something that does not change. For example, the contents of a Java character strings are immutable once defined.
- implementation
- the process of translating a design into source ode. The source code that defins a method, lass, abstrct data type, or other programming entity.
- implicit paramenter
- The object on which a non-static method is invoked. For example in the method invocation myAccount.deposit(100), myAccount is the implicit parameter.
- initialize
- togive an intial value to a variable
- instance
- an object created from a class. Multiple objects can be instantiated from a single class
- instance variable
- each instance of a class has its own ersion of the variable.
- instantiation
- the act of creating an object from a class
- interpreter
- a program that translates and executes code on a particular machine
- instruction register
- holds a copy of the instruction fetched from memory.
- instruction set
- set of all operations that can be executed by a processor (what to include)
- Java
- programming language that is object oriented, robust, secure, architecture neutral, protable, high-performance, interpreted, threaded, and dynamic
- JVM
- Java Virtual Machine - the conceptual device, implemented in software, on which java bytecode is executed.
- local variabled
- a variable declared inside a method that does not exist outside of that method.
- loop control variable
- break!
- machine language
- the native language of a particular CPU
- mass storagedata
- data storeage on a system that is non-volatile in nature
- memory location
- an individual, addressable cell inside the main memory into which data can be stored.
- method
- a named group of declarations and programming statements that can be invoked (executed) when needed. part of a class
- Method invocation
- a line of code that causes a method to be executed. It specifies any values that are passed to the method as parameters.
- mutator method
- a method that changes the value of the argument variables
- null
- a Java reserved word that is a reference literal, used to indicate that a reference does nto currently refer to any object.
- object
- an encapsulated collection of data variables and methods. an instance of a classx[
- OOP
- an approach to software design and implementation that is centered around objects and classes
- op code
- unique unsigned integer code assigned to each machine language operation recognized by the hardware.
- overloading
- assinging additional meanign to a programming lanuge construct, such as a method
- parameter
- a value passed from a method invocation to its definition
- pointer
- a variable that can hold a memory address (references)
- portability
- the ability of a program to be moved from one hardware platform to another w/o having to change it
- primitive data type
- a data type that is predefined in a programming language
- procedural programming
- an approach to software design and implementation that is centered around procedures(or functions) and their interaction
- program
- a series of instructions executed by hardware, one after another.
- pseudocode
- structured and abbreviated natural language used to express the algorithmic steps of a program.
- RAM
- random access memory a term basically interchangeable with main memory
- reference
- a variable that holds the address of an object. In java, a reference can be used to interact with an object.
- register
- a small area of storage in the CPU of the computer
- SASD
- sequential access storage device - all data must be searched (no addresses) like a tape
- scope
- the area within a program in whih an identifier, such as a variable, can be referenced. "where a variable lives"
- static
- a modifier of methods and variables. can be referenced w/o an instance of a class.
- stored programming concept
- the instructions to be executed by the computre are represented as binary values and stored in memory.
- syntax
- rules of a language - must follow an order
- unicode
- internation character set used to define valid Java characters. Each character is represented using a 16-bit unsigned numeric value
- variable
- an identifier in a program that represents a memory location in whcih a data value is stored.
- Von Neumann architecture
- programs and data are stored teogether in the same memory devices.
- white space
- used to set off sections of source code to make programs more readable.