Constant vs. Variable — What's the Difference?
By Tayyaba Rehman — Published on September 16, 2023
A constant remains unchanged over time, while a variable is subject to change. Constant denotes stability and permanence and variable implies dynamism and change.
Difference Between Constant and Variable
Table of Contents
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Key Differences
In the realms of mathematics and science, a constant represents a value that does not change. Once its value is defined, it remains fixed for the entirety of the discussion or experiment. Conversely, a variable stands as a symbol that can represent different values; it varies based on conditions or equations.
While the term constant denotes stability and permanence, the term variable implies dynamism and change. A constant's primary characteristic is its unwavering nature, whether in mathematical equations, scientific experiments, or everyday scenarios. On the other hand, the essence of a variable is its flexibility and adaptability.
Take a scientific experiment as an instance: when studying the effect of light on plant growth, if the amount of water given to each plant remains the same throughout the experiment, it is a constant. Meanwhile, the amount of light, if it changes for different groups of plants, becomes the variable.
In programming, a constant might refer to a value that a developer decides should not be altered as the code executes, ensuring consistency. In contrast, a variable in programming holds data that can change as the program runs, offering flexibility.
Comparison Chart
Definition
A value that does not change.
A symbol that can represent different values.
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Nature
Unchanging.
Subject to change.
Usage
Represents fixed values in equations.
Holds changeable data in equations.
Example Scenario
Water amount in a plant experiment.
Light exposure in a plant experiment.
Role in Programming
Value not altered during code execution.
Holds data that can change during execution.
Compare with Definitions
Constant
Permanent and unvarying.
His constant dedication to the project ensured its success.
Variable
A symbol representing an unknown value in mathematics.
In the equation x + 5 = 10, x is the variable.
Constant
Not changing or varying; continuous
A constant gentle rain.
Drove at a constant speed.
Variable
An element or factor that can change.
In our experiment, temperature was the main variable.
Constant
Happening regularly or repeatedly; continual
The constant barking of the dog next door.
Constant interruptions.
Variable
Likely to change or vary; subject to variation; changeable.
Constant
Unchanging in nature, value, or extent; invariable
A constant wind speed.
Variable
Inconstant; fickle.
Constant
Steadfast in purpose, loyalty, or affection; faithful
A constant friend.
Variable
(Biology) Tending to exhibit genetic variation or variation in a physical trait
Geographically variable color patterns.
Constant
Something that is unchanging or invariable.
Variable
(Mathematics) Having no fixed quantitative value.
Constant
A quantity assumed to have a fixed value in a specified mathematical context.
Variable
Something that varies or is prone to variation.
Constant
An experimental or theoretical condition, factor, or quantity that does not vary or that is regarded as invariant in specified circumstances.
Variable
(Astronomy) A variable star.
Constant
Unchanged through time or space; permanent.
Variable
A quantity capable of assuming any of a set of values.
Constant
Consistently recurring over time; persistent.
Variable
A symbol representing such a quantity. For example, in the expression a2 + b2 = c2, a,b, and c are variables.
Constant
Steady in purpose, action, feeling, etc.
Variable
Able to vary or be varied.
Variable winds or seasons; a variable quantity; a variable resistor
Constant
Firm; solid; not fluid.
Variable
Likely to vary.
Constant
(obsolete) Consistent; logical.
Variable
Marked by diversity or difference.
Constant
Bounded above by a constant.
Constant time
Constant space
Variable
(mathematics) Having no fixed quantitative value.
Constant
That which is permanent or invariable.
Variable
(biology) Tending to deviate from a normal or recognized type.
Constant
(algebra) A quantity that remains at a fixed value throughout a given discussion.
Variable
Something that is variable.
Constant
(science) Any property of an experiment, determined numerically, that does not change under given circumstances.
Variable
Something whose value may be dictated or discovered.
There are several variables to consider here.
Constant
(computing) An identifier that is bound to an invariant value; a fixed value given a name to aid in readability of source code.
Variable
(mathematics) A symbol representing a variable.
Constant
Firm; solid; fixed; immovable; - opposed to fluid.
If . . . you mix them, you may turn these two fluid liquors into a constant body.
Variable
(programming) A named memory location in which a program can store intermediate results and from which it can read them.
Constant
Not liable, or given, to change; permanent; regular; continuous; continually recurring; steadfast; faithful; not fickle. Opposite of changeable and variable.
Both loving one fair maid, they yet remained constant friends.
I am constant to my purposes.
His gifts, his constant courtship, nothing gained.
Onward the constant current sweeps.
Variable
(astronomy) A variable star.
Constant
Remaining unchanged or invariable, as a quantity, force, law, etc.
Variable
(nautical) A shifting wind, or one that varies in force.
Constant
Consistent; logical.
Variable
Those parts of the sea where a steady wind is not expected, especially the parts between the trade-wind belts.
Constant
That which is not subject to change; that which is invariable.
Variable
Having the capacity of varying or changing; capable of alternation in any manner; changeable; as, variable winds or seasons; a variable quantity.
Constant
A quantity that does not change its value; - used in countradistinction to variable.
Variable
Liable to vary; too susceptible of change; mutable; fickle; unsteady; inconstant; as, the affections of men are variable; passions are variable.
Lest that thy love prove likewise variable.
His heart, I know, how variable and vain!
Constant
A number whose value, when ascertained (as by observation) and substituted in a general mathematical formula expressing an astronomical law, completely determines that law and enables predictions to be made of its effect in particular cases.
Variable
That which is variable; that which varies, or is subject to change.
Constant
A number expressing some property or condition of a substance or of an instrument of precision; as, the dielectric constant of quartz; the collimation constant of a transit instrument.
Variable
A quantity which may increase or decrease; a quantity which admits of an infinite number of values in the same expression; a variable quantity; as, in the equation x2 - y2 = R2, x and y are variables.
Constant
A data structure that does not change during the course of execution of a program. It may be a number, a string, or a more complex data structure; - contrasted with variable.
Variable
A shifting wind, or one that varies in force.
Constant
A quantity that does not vary
Variable
Something that is likely to vary; something that is subject to variation;
The weather is one variable to be considered
Constant
A number representing a quantity assumed to have a fixed value in a specified mathematical context;
The velocity of light is a constant
Variable
A quantity that can assume any of a set of values
Constant
Persistent in occurrence and unvarying in nature;
Maintained a constant temperature
A constant beat
Principles of unvarying validity
A steady breeze
Variable
A star that varies noticeably in brightness
Constant
Continually recurring or continuing without interruption;
Constant repetition of the exercise
Constant chatter of monkeys
Variable
A symbol (like x or y) that is used in mathematical or logical expressions to represent a variable quantity
Constant
Steadfast in purpose or devotion or affection;
A man constant in adherence to his ideals
A constant lover
Constant as the northern star
Variable
Liable to or capable of change;
Rainfall in the tropics is notoriously variable
Variable winds
Variable expenses
Constant
Uninterrupted in time and indefinitely long continuing;
The ceaseless thunder of surf
In constant pain
Night and day we live with the incessant noise of the city
The never-ending search for happiness
The perpetual struggle to maintain standards in a democracy
Man's unceasing warfare with drought and isolation
Unremitting demands of hunger
Variable
Marked by diversity or difference;
The varying angles of roof slope
Nature is infinitely variable
Constant
A value that remains the same over time.
The speed of light in a vacuum is a universal constant.
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
Constant
Something that remains unchanged in equations.
In the equation E=mc^2, c is the constant representing the speed of light.
Variable
Something that differs or changes based on conditions.
Economic growth is a variable dependent on multiple factors.
Constant
Unchanging under different conditions.
No matter how much pressure you apply, the boiling point of water at sea level remains a constant.
Variable
Liable to vary or change.
Weather is a variable factor in outdoor planning.
Constant
Continual; regularly recurring.
Her constant chatter kept him entertained during the long drive.
Variable
Not consistent or having a fixed pattern.
The variable performance of the team led to unpredictable results.
Common Curiosities
In what scenarios might a Variable be used?
Variables are used in mathematical equations, scientific experiments, and programming to represent changeable values.
What is a Constant?
A constant is a value that remains unchanged over time.
Can a Constant ever change?
By definition, a constant remains fixed and does not change.
Are there any famous Constants in science?
Yes, like the gravitational constant (G) or Planck's constant (h).
In algebra, how do we typically represent Variables?
Variables are usually represented by letters, such as x, y, or z.
Do all equations have both Constants and Variables?
Not necessarily. Some equations might only have constants, some only variables, and some both.
How do Variables enhance flexibility in equations?
Variables allow for different values to be plugged in, accommodating various scenarios or conditions.
Can a Variable become a Constant in different scenarios?
Yes, if a previously changeable value is fixed in a different context, it can act as a constant.
How is a Variable defined?
A variable is a symbol or element that can represent different values and is subject to change.
Why is it important to distinguish between Constant and Variable?
Distinguishing helps in understanding stability versus change in contexts like mathematical problems or scientific experiments.
Are there constants in programming?
Yes, constants in programming are values set to remain unchanged during the code's execution.
Is the term "constant" only used in mathematics and science?
No, it's used in everyday language to describe something unchanging or continual.
Why are Variables crucial in research?
Variables allow researchers to test hypotheses, study relations, and observe effects under varying conditions.
How do Constants contribute to the reliability of experiments?
By keeping certain elements constant, researchers can ensure that observed changes are due to the variable being tested.
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Written by
Tayyaba RehmanTayyaba Rehman is a distinguished writer, currently serving as a primary contributor to askdifference.com. As a researcher in semantics and etymology, Tayyaba's passion for the complexity of languages and their distinctions has found a perfect home on the platform. Tayyaba delves into the intricacies of language, distinguishing between commonly confused words and phrases, thereby providing clarity for readers worldwide.
