Variable

Variable

In computing, a variable is a data value that can be changed or adjusted as needed. It can be used to refer to an item of data that changes in value over time, such as a counter, or to refer to an item of data whose value can be determined from some other source, such as a user input or a calculation. Variables are used to store information that can be reused in computer programs, such as when a user provides input to a program or when a program needs to calculate the output.

Variables are the basic building blocks of all programming languages, and they are used to store and manipulate data. Each variable has its own name and data type, which determines how the data stored in the variable is to be used. Common data types include integers, characters, and strings. For example, an integer might refer to a number, while a character might refer to a letter or symbol. A string is a series of characters that functions like a a collection of data that can be manipulated.

In addition to storing data, variables are also used in performing calculations. Most programming languages allow for the use of mathematical operators, such as additions, subtraction, multiplication, and divisions, to be used in combination with variables to calculate the result of an expression. For example, the following expression (in JavaScript):

var a = 10
var b = 20
var c = a + b

The result of this expression is “30”, as the variable “c” now holds the sum of the two other variables, “a” and “b”. Variables can be used in more complex expressions, such as in conditional statements, which allow for the execution of certain tasks depending on the evaluation of a logical expression.

Variables are one of the essential elements of programming, and without them most computer programs could not execution. For a program to be able store and manipulate data, it must be able to store the data in a way that can be recalled and manipulated later. Variables provide the means to do this.