Difference Between Constants and Variables

Last Updated : Sep 4, 2022 / By Sandeep Bhandari / Fact Checked / 3 mins

Constants have multiple meanings, and it is fixed concerning floating-point value. It is used for two purposes: a fixed number that is well-defined and second as a constant function whose value remains unchanged.

Variables are something that is a type of quantity that changes and can vary according to an equation. Variables are also used to represent functions, matrices, vectors and numbers.

Comparison Table Between Constants and Variables 

Parameters of Comparison	Constants	Variables
Value in Maths	It is a constant or fixed number.	It is an undefined number.
Value in Programming	It is any data that is unchanged.	It is any data that is changing.
Symbol in Maths	It has numbers as a symbol.	It has letters and symbols.
Symbol in Programming	It has defined a constant name.	It has a defined variable name.
Types	There are 4 types of constants.	There are two types of variables.

What are Constants?

Constants can be defined as a constant function that gives the same value always. If a constant is written in a single variable, for example, f(x) = 5, it would make a graph with a horizontal straight line parallel to the x-axis.

In programming, the value of a constant cannot be changed by program, and value remains constant. When constant are put together by an identifier, it is called ‘named’.

Constants are used in many programming languages such as C, C++, Java etc. Programming paradigms define that how the values of constants should be treated.

What are Variables?

Variables are used commonly for representing vectors, functions and matrices. It is used to show the arbitrary value of a set. The value of variables keeps changing, unlike constants.

In the 16th century, François Viète gave the idea of representing variables with letters and using it in computer programming as well. Then Rene Descartes uses the methodology to use variables for an unknown in an equation like a, b or c. In maths, it is very common that variables play different roles, like in differential calculus. Concerning the variable, it is also called arguments of functions. Variables are also defined as independent of x ad can be called constants.

In programming variables are scalar are used as storage devices to store various types of data. It is paired with a symbolic code that has an unknown or known quantity.

Main Differences Between Constants and Variables

1. Constants have been defined as a constant name in programming. Variables have been as a defined variable name in Programming.
2. There are 4 types of constants i.e. Integer, Character, Real and String Constants. There are two types of variables: Independent and Dependent Variables.

Conclusion

Both are very integral parts of these two areas and are used in various applications, whether it be physics, Programming language etc.

Both Constants and Variables are represented in either Greek or English letters. Variables have a changing magnitude, and their value is unknown.

References

1. https://europepmc.org/article/med/2304410
2. https://academic.oup.com/ia/article-abstract/85/6/1143/2326220