variable

var·i·a·ble

V0028000 (vâr′ē-ə-bəl, văr′-)adj.1. a. Likely to change or vary; subject to variation; changeable.b. Inconstant; fickle.2. Biology Tending to exhibit genetic variation or variation in a physical trait: geographically variable color patterns.3. Mathematics Having no fixed quantitative value.n.1. Something that varies or is prone to variation.2. Astronomy A variable star.3. Mathematics a. A quantity capable of assuming any of a set of values.b. A symbol representing such a quantity. For example, in the expression a² + b² = c², a,b, and c are variables.

var′i·a·ble·ness n.var′i·a·bly adv.

variable

(ˈvɛərɪəbəl) adj1. liable to or capable of change: variable weather. 2. (of behaviour, opinions, emotions, etc) lacking constancy; fickle3. (Mathematics) maths having a range of possible values4. (Biology) (of a species, characteristic, etc) liable to deviate from the established type5. (Physical Geography) (of a wind) varying its direction and intensity6. (Electrical Engineering) (of an electrical component or device) designed so that a characteristic property, such as resistance, can be varied: variable capacitor. n7. something that is subject to variation8. (Mathematics) maths a. an expression that can be assigned any of a set of valuesb. a symbol, esp x, y, or z, representing an unspecified member of a class of objects, numbers, etc. See also dependent variable, independent variable9. (Logic) logic a symbol, esp x, y, z, representing any member of a class of entities10. (Computer Science) computing a named unit of storage that can be changed to any of a set of specified values during execution of a program11. (Celestial Objects) astronomy See variable star12. (Physical Geography) a variable wind13. (Physical Geography) (plural) a region where variable winds occur[C14: from Latin variābilis changeable, from variāre to diversify] ˌvariaˈbility, ˈvariableness n ˈvariably adv

var•i•a•ble

(ˈvɛər i ə bəl)

adj. 1. apt to vary; changeable. 2. capable of being varied. 3. inconstant; fickle. 4. having much variation or diversity. 5. deviating from the usual type, as a species. 6. (of a star) changing in brightness. 7. (of wind) tending to change in direction. 8. having the characteristics of a variable. n. 9. something that may vary. 10. a. a quantity or function that may assume any given value or set of values. b. a symbol that represents this. 11. a symbol in logic for an unspecified member of a class of things or statements. 12. a shifting wind. [1350–1400; < Late Latin] var`i•a•bil′i•ty, var′i•a•ble•ness, n. var′i•a•bly, adv.

var·i·a·ble

(vâr′ē-ə-bəl)1. A mathematical quantity capable of assuming any of a set of values, such as x in the expression 3x + 2.2. A factor or condition that is subject to change, especially one that is allowed to change in a scientific experiment to test a hypothesis. See more at control.

variable

A condition, such as temperature, concentration and pressure, which can be changed in a chemical reaction.

Thesaurus

Noun	1.	variable - something that is likely to vary; something that is subject to variation; "the weather is one variable to be considered"thing - a separate and self-contained entity
	2.	variable - a quantity that can assume any of a set of valuesvariable quantityquantity - the concept that something has a magnitude and can be represented in mathematical expressions by a constant or a variableargument - a variable in a logical or mathematical expression whose value determines the dependent variable; if f(x)=y, x is the independent variableexperimental variable, independent variable - (statistics) a variable whose values are independent of changes in the values of other variablescorrelate, correlative - either of two or more related or complementary variablesdegree of freedom - (statistics) an unrestricted variable in a frequency distributiondependent variable - (statistics) a variable in a logical or mathematical expression whose value depends on the independent variable; "if f(x)=y, y is the dependent variable"predictor variable - a variable that can be used to predict the value of another variable (as in statistical regression)infinitesimal - (mathematics) a variable that has zero as its limitchance variable, random variable, stochastic variable, variate, variant - a variable quantity that is randomscalar - a variable quantity that cannot be resolved into componentstensor - a generalization of the concept of a vectorvector - a variable quantity that can be resolved into components
	3.	variable - a star that varies noticeably in brightnessvariable starstar - (astronomy) a celestial body of hot gases that radiates energy derived from thermonuclear reactions in the interior
	4.	variable - a symbol (like x or y) that is used in mathematical or logical expressions to represent a variable quantitysymbol - an arbitrary sign (written or printed) that has acquired a conventional significanceplaceholder - a symbol in a logical or mathematical expression that can be replaced by the name of any member of specified setunknown quantity, unknown - a variable whose values are solutions of an equation
Adj.	1.	variable - liable to or capable of change; "rainfall in the tropics is notoriously variable"; "variable winds"; "variable expenses"inconsistent - displaying a lack of consistency; "inconsistent statements cannot both be true at the same time"; "inconsistent with the roadmap"inconstant - likely to change frequently often without apparent or cogent reason; variable; "inconstant affections"; "an inconstant lover"; "swear not by...the inconstant moon"- Shakespeareinvariable - not liable to or capable of change; "an invariable temperature"; "an invariable rule"; "his invariable courtesy"
	2.	variable - marked by diversity or difference; "the varying angles of roof slope"; "nature is infinitely variable"varyingvaried - characterized by variety; "immigrants' varied ethnic and religious traditions"; "his work is interesting and varied"
	3.	variable - (used of a device) designed so that a property (as e.g. light) can be varied; "a variable capacitor"; "variable filters in front of the mercury xenon lights"adaptable - capable of adapting (of becoming or being made suitable) to a particular situation or use; "to succeed one must be adaptable"; "the frame was adaptable to cloth bolts of different widths"

variable

adjective changeable, unstable, fluctuating, shifting, flexible, wavering, uneven, fickle, temperamental, mercurial, capricious, unsteady, protean, vacillating, fitful, mutable, inconstant, chameleonic Weather conditions are variable and change from day to day.
stable, constant, unchanging, firm, settled, fixed, steady, unalterable

variable

adjective1. Capable of or liable to change:alterable, changeable, fluid, inconstant, mutable, uncertain, unsettled, unstable, unsteady, variant.Archaic: various.2. Following no predictable pattern:capricious, changeable, erratic, fantastic, fantastical, fickle, freakish, inconsistent, inconstant, mercurial, temperamental, ticklish, uncertain, unpredictable, unstable, unsteady, volatile, whimsical.3. Lacking consistency or regularity in quality or performance:erratic, inconsistent, patchy, spotty, uneven, unsteady.

Translations

变化变化的可变的易变的

vary

(ˈveəri) verb to make, be or become different. These apples vary in size from small to medium.变化ˈvariable adjective1. that may be varied. The machine works at a variable speed.可变的2. (of eg winds, weather etc) liable or likely to change. British weather is very variable.易变的 noun something that varies, eg in quantity, value, effect etc. Have you taken all the variables into account in your calculations?变化ˈvariably adverb可变地ˌvariaˈbility – plural variaˈbilities – noun 可变性，易变性，变异性 ˌvariˈation noun1. the extent to which a thing changes. In the desert there are great variations in temperature.变化2. one of a series of musical elaborations made on a basic theme or melody. Brahms' variations on Haydn's `St Anthony's Chorale'. 变奏（曲） ˈvaried adjectiveHe has had a very varied career.各种各样的

variable

→ 变化的zhCN

variable

1. Maths having a range of possible values 2. (of a species, characteristic, etc.) liable to deviate from the established type 3. (of a wind) varying its direction and intensity 4. (of an electrical component or device) designed so that a characteristic property, such as resistance, can be varied 5. Mathsa. an expression that can be assigned any of a set of values b. a symbol, esp x, y, or z, representing an unspecified member of a class of objects, numbers, etc. 6. Logic a symbol, esp x, y, z, representing any member of a class of entities 7. Computing a named unit of storage that can be changed to any of a set of specified values during execution of a program 8. a variable wind 9. a region where variable winds occur

variable

Short for variable star.

variable

a characteristic which can be measured and which may vary along a continuum, continuous variable (e.g. height), be more discrete (e.g. family size) or be bipolar (e.g. sex). The term is commonly used in empirical social research to denote the representation of a social factor such as age, social class, employment status, years of education, which can be observed to affect other measures, such as income level (which may be influenced by all of those mentioned). Social and psychological research is particularly interested in defining what aspects of society or experience influence other social parameters or behaviours, with the intention of explaining social phenomena. On one view, for this to be managed scientifically, possible influences and possible effects have to be defined and quantified so that methods such as concomitant variation, survey research or experiment can be set up to test HYPOTHESES. It is these definitions and quantifications that result in the variables which are used in scientific data analysis. It should be noted that continuous variables are measured on an interval scale, while discrete variables often use nominal or ordinal measurement (see CRITERIA AND LEVELS OF MEASUREMENT).

In some traditions in sociology, however, the appropriateness of the concept of the variable in the above sense has been questioned. From the perspective of SYMBOLIC INTERACTIONISM, for example, Herbert BLUMER (1956) has suggested that the use of standardized variables in social analysis leads to a neglect of the close study required for the effective study of social situations and a distorted representation of social reality. Similar scepticism is voiced in approaches such as ETHNOMETHODOLOGY (see also MEASUREMENT BY FIAT, OFFICIAL STATISTICS).

Variable

a fundamental concept of mathematics and logic. Beginning with the works of P. de Fermat, R. Descartes, I. Newton, G. W. von Leibniz, and other founders of higher mathematics, a variable was understood as a quantity that can vary—in the process of this variation it takes on different values. Variables were thus contrasted with constants—numbers or other quantities each of which has a unique, completely defined value. As mathematics developed and work proceeded on its foundations, great pains were taken to exclude such concepts as processes and variation of quantities from the vocabulary of mathematics as being extramathematical. The variable consequently came to be interpreted as a symbol for an arbitrary element of the domain of objects under consideration—for example, the domain of natural numbers or of real numbers. In other words, a variable was now seen as a generic name for the entire domain; constants, on the other hand, were proper names for numbers or other specific objects in the domain under consideration.

This revision of the concept of variable was closely connected with the reorganization of mathematics on the foundation of set theory, a process that was completed in the late 19th century. For all the simplicity and naturalness of this reorganization, it was essentially based on the abstraction of actual infinity. This abstraction permitted arbitrary infinite sets to be considered as “given” (“completed,” “ready,” “actual”) objects, to which all the methods of classical logic could be applied without regard for the incompletedness and the fundamental impossibility of completing the process of the formation of such a set. The difficulties in solving the logical problems associated with the adoption of this abstraction make understandable the partial rehabilitation of the old concepts of variable quantities. In constructing mathematical theories, the representatives of some schools, such as mathematical intuitionism and the constructive trend, have preferred to make do with the weaker, but logically less vulnerable, abstraction of potential realizability. This point of view associates infinite sets with the concepts of the processes of the sets’ generation—processes that go as far as desired but never end. When investigating the problem of the consistency of different fields of mathematics, most mathematicians and logicians in effect adopt this position.

In formalized languages (calculi, or formal systems) of mathematical logic, the term “variable” is applied to any symbol of a strictly fixed type that under certain conditions permits an expression of the given calculus to be substituted for it. Such variables are called free variables. An example is the variable x in the inequality x > 5. If, say, the numeral (that is, the symbol of the number) 7 is substituted for x, the inequality becomes a true statement; if the numeral 2 is substituted, the inequality becomes a false statement. What are called bound variables do not mean anything in themselves but perform purely syntactical functions; when certain elementary precautions are observed, bound variables can be “renamed”—that is, they can be replaced by other variables. An example is the variable y in the expressions

in the interpretations of which y does not appear and can be replaced by any other variable. Thus, the first expression, which can be read “the sum of the integers from 5 through 25,” can be replaced by

The second expression, which might be read “all numbers have the property p,” can be replaced by ∀tP(t). Individual, proposition, predicate, function, number, and other types of variables are distinguished. They can be replaced, in accordance with special substitution rules, by symbols for, respectively, the objects from the domain under consideration (“terms”), specific statements, predicates, functions, numbers, and so on. Thus, a variable in a formula can be meaningfully understood as an empty place equipped with an indication that the place can be filled—the variable is like a container for a strictly defined piece of merchandise.

Free occurrences of variables in the expressions of meaningful scientific theories and in the formulas of logical and mathematical calculi correspond to the use of indefinite pronouns in ordinary speech and permit of different interpretations. One type of interpretation, which corresponds to the use of a variety of substitution procedures, is the predicate interpretation: the formula A (x₁, … x_n) of some calculus is interpreted as an n-place predicate. The same formula can also be interpreted as a proposition, or statement, specifically as the proposition ∀x₁ … ∀x_nA (x₁, …, x_n), which is a “closure” of the formula—this is the interpretation of universality, which is commonly used, for example, in formulating the axioms of various scientific theories. Finally, to free variables there can be ascribed values constant within some context—for example, the context of a conclusion from a given set of formulas. The variables are then called the parameters of the context, and we speak of the conditional interpretation. For example, the variable x in the expression cos x, taken in isolation, has a predicate interpretation. In the identity sin²x + cos²x = 1 it has the interpretation of universality. In the equation cos x = 1 (in the process of solving this equation, when the variable is called an “unknown”) it has the conditional interpretation.

Thus, at different levels of formalization the concept of the variable acts as a refinement of means commonly used in ordinary spoken languages—such as indefinite pronouns and indefinite articles—and of various methods of employing these means.

REFERENCES

Kleene, S. C. Vvedenie ν metamatematiku, subsecs. 31, 32, 45. Moscow, 1957. (Translated from English.)
Church, A. Vvedenie ν matematicheskuiu logiku, vol. 1, subsecs. 02, 04, 06. Moscow, 1960. (Translated from English.)

variable

[′ver·ē·ə·bəl] (computer science) A data item, or specific area in main memory, that can assume any of a set of values. (mathematics) A symbol which is used to represent some undetermined element from a given set, usually the domain of a function.

variable

(programming)(Sometimes "var" /veir/ or /var/) A named memorylocation in which a program can store intermediate results andfrom which it can read it them. Each programming languagehas different rules about how variables can be named, typed,and used. Typically, a value is "assigned" to a variable inan assignment statement. The value is obtained byevaluating an expression and then stored in the variable. Forexample, the assignment

x = y + 1

means "add one to y and store the result in x". This may looklike a mathematical equation but the mathematical equality isonly true in the program until the value of x or y changes.Furthermore, statements like

x = x + 1

are common. This means "add one to x", which only makes senseas a state changing operation, not as a mathematical equality.

The simplest form of variable corresponds to a single-wordof memory or a CPU register and an assignment to aload or store machine code operation.

A variable is usually defined to have a type, which neverchanges, and which defines the set of values the variable canhold. A type may specify a single ("atomic") value or acollection ("aggregate") of values of the same or differenttypes. A common aggregate type is the array - a set ofvalues, one of which can be selected by supplying a numericalindex.

Languages may be untyped, weakly typed, strongly typed,or some combination. Object-oriented programming languagesextend this to object types or classes.

A variable's scope is the region of the program sourcewithin which it represents a certain thing. Scoping rules arealso highly language dependent but most serious languagessupport both local variables and global variables.Subroutine and function formal arguments are specialvariables which are set automatically by the language runtimeon entry to the subroutine.

In a functional programming language, a variable's valuenever changes and change of state is handled as recursion overlists of values.

variable

A structure that holds data within an executable program. Mostly created by and uniquely named by the programmer, variables may store predefined data at the start of the program or be empty containers until a value is placed in them. The values may remain constant or be updated in RAM as the program runs. Variables are used as counters to sum totals and do math as well as to keep track of processes that are repeated within the program. There may be dozens or hundreds of variables defined in a single application.

Using C/C++ as the example language, the statement int counter; defines an integer variable for whole numbers named COUNTER. The statement counter=1; stores a 1 in COUNTER, and counter++; adds 1 to COUNTER. A "char" variable holds character data. A single character variable requires single quotes, but a "string" of characters uses double quotes; for example, mode='A'; and product="abc"; places A in the variable MODE and ABC in PRODUCT. See string, integer and RAM.

Variables Are Control Values
Variables are widely used to repeat a process. In the following for statement, the function DO-SOMETHING is performed five times. At first, x is set to 0. All statements between the left and right curly braces ({ }) are performed. Then, x is incremented by 1 until x is no longer less than 5.

for (x=0; x<5; x++) { do-something(); }

Local and Global Variables
A local variable is one that is referenced only within the subprogram, function or procedure it was defined in. A global variable can be used by the entire program. See environment variable, undefined variable and local variable.

Actual Variable Examples
The following integer variables and character strings were extracted from a program written in C that converts an XML encyclopedia feed to an HTML feed. The =NO is the same as inserting a 0. Variables are often used to keep track of internal modes that are turned on and off while the program is running. YES and NO are the same as 1 and 0 to the compiler.

int ForceOne=NO, ForceAll=NO, NoMoreFiles=NO;int XMLfileNewer=NO, EndFile=NO;int TermsWith1Link=0, TermsWith2Links=0;int TermsWith3Links=0, TermsWithNoLinks=0;int AFTermCount=0;int AF_results=0;int AF_EOF=0;int hFileAF;int ARTICLES=0;char AFbuff[2000];char *AFptr;char HREF1buff[500];char HREF2buff[500];char HREF3buff[500];

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REFERENCES

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Synonyms for variable

adj changeable

Synonyms

Antonyms

Synonyms for variable

adj capable of or liable to change

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adj following no predictable pattern

Synonyms

adj lacking consistency or regularity in quality or performance

Synonyms

Synonyms for variable

noun something that is likely to vary

Related Words

noun a quantity that can assume any of a set of values

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Related Words

noun a star that varies noticeably in brightness

Synonyms

Related Words

noun a symbol (like x or y) that is used in mathematical or logical expressions to represent a variable quantity

Related Words

adj liable to or capable of change

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Antonyms

adj marked by diversity or difference

Synonyms

Related Words

adj (used of a device) designed so that a property (as e.g. light) can be varied

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