Difference Between Constants and Variables (With Table)

Mathematics is an important topic, but it doesn’t have any precise definition. It includes geometry, quantity, space and Change. Mathematics uses a pattern to formulate a conclusion or a proposition by checking the truth or false by proof. By calculating, counting, and measurement, Mathematics develops. Computer Programming is also a type of Mathematics only. Constant and Variables are the two important part of mathematics. Without which all the Mathematics would be vague and unclear.

Constants vs Variables

The difference between constant and variable is that Constants doesn’t change their value, and their value is fixed. Whereas Variables changes their value frequently depending upon the equation. Constants and Variables are used in both Computer Science and Mathematics. Both have slight differences in the two areas. A Constant function is defined by a rule known as a Constant Rule. Variables are of two types i.e. independent variable and dependant variable.

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. Besides being used in mathematics, it is also used in computer programming in which the value of constants should not be altered during the program when it is going through an execution.

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. Variables help us to solve a lot of problems with a single equation. In mathematics, the variable is a symbol whose value is undefined. In programming, the variable is a type of container for different types of data.

Comparison Table Between Constants and Variables 

Parameters of ComparisonConstantsVariables
Value in MathsIt is a constant or fixed number. It is an undefined number.
Value in ProgrammingIt is any data that is unchanged.It is any data that is changing.
Symbol in MathsIt has numbers as a symbol.It has letters and symbols.
Symbol in ProgrammingIt has defined a constant name.It has a defined variable name.
TypesThere 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. Whenever its value is taken, it will give the same result no matter what. In mathematics, Constants are defined by specific symbols when values occur to like 0(zero), 1(one), π (pi), (square root of 2),φ (golden ratio).

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’. Constant is very helpful as it can be used both in compilers as well as for programmers. Programmers use it for self-documenting code, and compilers use it for run-time checks and compile time. A constant value can be defined once, but it can be used many times when the program is running.

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. There are four types of Constants in the C Programming language, i.e., integer constants, Character constants, Real/Floating-point constants, string constants. Integer constants uses digits like -3, -1, 0 etc. Characters Constants define characters in single quotes like ‘a’, ‘8’, ‘25’ etc. Real or Floating-point constants use decimal or an exponent. String Constants also use characters but in double quotations.

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. The term ‘Variable’ comes from the Latin word variābilis, which means it keeps changing. It was for the first time found in the book written by Brahmagupta in the 7th century named Brāhmasphuṭasiddhānta. It was used to represent the unknown value in algebraic equations.

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. The variable of programming is slightly different from the variable of mathematics. Like variables in programming are given very long names, whereas in mathematics, it of one or two characters. There are different types of variables like static, stack-dynamic, implicit heap-dynamic and explicit heap-dynamic.

Main Differences Between Constants and Variables

  1. Value of Constants in maths is fixed or constant in numbers. The value of variables in maths is an undefined number
  2. Value of Constants in Computer Programming is any unchanged type of data. Value of variables in Computer programming is any type of data that is changing.
  3. Constants have numbers as a symbol in maths. Variables have letters and symbols in maths.
  4. Constants have been defined as a constant name in programming. Variables have been as a defined variable name in Programming.
  5. There are 4 types of constants i.e. Integer, Character, Real and String Constants. There are two types of variables: Independent and Dependent Variables.


Both Constants and Variables are used as an important factor in mathematics and programming. 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. Whereas as the name defines, Constants are constants with unchanging value, but their face value is known.


  1. https://europepmc.org/article/med/2304410
  2. https://academic.oup.com/ia/article-abstract/85/6/1143/2326220
2D vs 3D