What is a variable in programming? Learn more about the language of the future

You still don’t know what a variable in programming is, but you want to be an expert in web development in the future? don’t worry, we’ll get you out of trouble. Defining what a programming variable is is perhaps one of the most important concepts to learn about coding and create impressive projects .

In a nutshell, a variable in programming is commonly used, since it is a fundamental element to manage the information you decide to incorporate in the code. Without it, you will not be able to project the various components of your website or mobile application to users.

Therefore, the concept of variable in programming is one of the first definitions you learn in web programming. So, you can not miss this note in which we will explain what a programming variable is and how to use it once you start programming.

You will also learn about its characteristics, its types and how to create a variable in programming in the most important languages on the market.

shall we start? read on!

what is a variable in programming?

International Business Machines Corporation, a worldwide company such as IBM, proposes the following concept of a programming variable:

“A variable in programming is a data element whose value can change during the course of a program’s execution.”moreover, experts state that “the variable name must follow the naming convention of an identifier (alphabetic character or number and the underscore sign).”

In simpler words, if we want to explain what a variable is in programming we can say that it is a unit of data storage and retrieval with values that can change, which is identified by a unique name in the program code.

In addition, a variable in programming can be understood as a name that represents a value and is used periodically to store various types of data, which will be used in subsequent coding operations.

If we were to use an analogy to describe this concept, we would say that a variable in programming is the base of the pyramid, since it holds the fundamental components of all computer programs.

It also emphasizes that variables in programming are useful, above all, for assigning complex values and to avoid putting the same data over and over again, making the program code or JavaScript application unnecessarily long.

The same applies to the various types of programming languages, since they all have variables that serve the same function.

In short, what is a programming variable? In a nutshell, it can be said that it is an element that functions both to store data, as well as to assign and represent values in a programming expression. However, the main purpose of a variable in programming is to facilitate the programmer’s task.

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Now that you know what a variable in programming is, we will tell you what are its characteristics.

what are the characteristics of a variable in programming?

The research platform, Lifeder, recognizes that variables in programming have three main characteristics. Below, we explain what each of them implies so that you can better understand what a variable in programming is:

1. Memory allocation

When we defined what a programming variable is, we emphasized that it is an element of coding to store information, such as values and data. In programming, the computer assigns the variable a position in its memory, depending on the type of data it stores .

In other words, a variable in programming is a place in the computer’s memory, since, when the computer executes a program or an application, the variable will have access to this block of memory.

2. Declaration

When we talk about how to declare a variable in programming, we refer to assigning it a name and a type; in this way, the system will be able to give it an abstraction of the memory to store the data and its value .

Also, this will depend on the type of programming language being used, since the classification of the variable before using it is different in each one. For example, in the case of Javascript and C language, it does need to be declared; however, in programming languages such as Python, this is not necessary.

3. Scope

Depending on the characteristics of variables in programming, the scope can be used to determine the extent to which the information or value of a variable can be read or manipulated .

For example, in the case of global variables, the scope will be greater, since they have the capacity to work throughout the entire program. On the other hand, as for local variables, the scope only reaches its own function. It is also important to emphasize that the scope acts in a hierarchical way following a descending order.

Next, we will talk more in depth about these types of variables in programming.

what are the types of variables in programming?

Once we have defined what a variable is in programming, let’s differentiate its different types. Here we will present two different classifications.

According to the types of values

First, according to what is a variable in programming, these are elements that are responsible for storing data. Professor Sergio Agamez Negrete divides the variables in programming according to the type of value they contain.

1. Numeric

An example of programming variables are numerical variables. In them, as the name suggests, we can store numbers. In this case, you do not need to add quotation marks, only the digit .

Likewise, if you want to store decimal numbers, you only need to use the dot (.) between whole and fractional numbers, since there are programming languages in which commas (,) are used to add other data to the variable.

2. Text string

In the case of a variable in programming that stores text, it needs to be enclosed in quotation marks. They can be single or double quotation marks, but the use of single quotation marks is recommended, because there are times when double quotation marks cannot be used.

There are also two types of text strings:

Fixed-length string: you stipulate how many characters it will contain.
Variable length string: the length is not defined.

3. Boolean

what is a variable in Boolean programming? This term refers to a logical value, which, in the case of programming, represents the dichotomy of true and false.

Usually, to represent this value we use “true” or “false”, referring to true and false, respectively. Another way to represent this is with 0 and -1, which represent false and true, respectively. Now, it is important to emphasize that both values are always constants.

4. HTML elements

Also, you can use a variable in programming to select elements within the HTML of your program or application. You only need to give them an identifier (id). In the case of Javascript, you need to use a selector to assign the elements to the variable. The latter depends on the programming language and the software you use.

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5. Fixes

creating these programming variables is very easy! An array is basically a variable where you can store more than one element together with other variables. You only need to write the list in square brackets and separate each element with a comma .

To refer to a single element of the array you must refer to it from its index, which is automatically assigned to it. The index consists of the items of the array numbered from 0. So, if you want to select only one element of this variable in programming, you need to select the digit that corresponds to it by its position.

6. Objects

what is an object type variable in programming? To give you an idea, this is very similar to the previous type. The difference is that it will be placed between braces and inside it you can add properties and values .

For example, {color: green}, in which color corresponds to the property and green to the value.

7. Functions

Finally, a variable in programming can also store functions. But what is a function? Within the discipline of web programming, a function is defined as a way in which algorithms and expressions are grouped into symbolic codes to determine actions. In this case, to execute the variable, you need to place the reserved word function

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Global and local variables

On the other hand, IBM presents another classification of variables in programming. In this case, they are divided into two groups: global and local.

1. Global programming variables

Global variables are those that are not declared within the function definition and are visible and available to all statements in a script. But, what is a script?

According to Rootear, a portal specialized in web programming, a script “is a programming code, usually simple, that contains commands or orders that are executed sequentially. They are commonly used to control the behavior of a specific program”.

So, a variable in global programming can be used anywhere in the code of a program or application, outside the scope of any function. Usually, they are placed at the beginning of the program and all the functions that compose it can access it to read and write to it.

However, it is not recommended to use global variables, since they can generate collateral effects, such as unwanted alterations in the code, and they also go against the principles of programming.

2. Variables in local programming

On the other hand, what is a variable in local programming? Any variable in programming that is inside the braces of a function can be called a local variable.

In contrast to global variables, local variables belong to the parameter of a single specific function, so they can only be displayed and used within that function.

Likewise, local variables can only be manipulated within the function to which they belong. Although variable names and their identifiers must be unique, it is valid to name a local variable with the same name as a local variable of another function, as well as with the name of a global variable.

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Now that you know what a variable in programming is, its characteristics and types, we will show you how to declare a programming variable.

how to create a variable in programming?

creating a variable is very simple! According to Hosting Plus, Peruvian web specialized in hosting services, we must start declaring the variable to be able to use it while coding a program.

This process consists of indicating the name and type of the variable so that the programming language can use it properly. But, first, we must define what are the parts of a variable in programming.

Remember that a variable is composed of a space in the storage system, i.e. a memory, and a symbolic name, known as an identifier.

However, you must keep in mind that the composition of a variable will be different depending on the programming language. Below, we will tell you how to declare a variable in three of the most used programming languages: Java, C language and Python.

In the same way, we will leave you some examples of variables in programming.

how to declare a programming variable in Java?

In Java, it is necessary to declare a variable to be able to use it during the decoding of a program. To do this, the abbreviation vab is placed, followed by the symbol = and continuing with the value of the variable.

However, as stipulated above, when coding some types of variables in Java programming it is required to declare the values with quotation marks, braces and square brackets.

For example, as follows:

Numeric variable:

vab = 12

Text string variable:

vab = ‘hello’

Array variable:

vab = [1, 2, 3, false]

Object variable:

vab = {color: yellow, size: large}

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how to declare a programming variable in C Language?

As in the previous case, in the C language, you must also declare the variable before continuing with the web coding process. Otherwise, the program will not correctly identify the variable in question.

To begin with, we must define what a variable is in programming with the first term of the whole sequence, so you will know what type of variable it is. To do this, the following codes will help you:

nt (integer) if you want to work with numeric variables of integer values

float if you want to store numeric variables with decimals

char if you want to work with a single character

string if you want to store a text (several characters)

boolean if you want to store boolean values, i.e. true and false.

how to create a programming variable in Python?

Finally, variables in Python are created when they are first defined in the coding sequence, i.e. when you assign them a value. In this case, you must use the equals sign (=) to declare that value.

Then, to the left of it, you must write the name of the variable in programming. Then, to the right, you must indicate the value that you will give to it.

Now, in the Python language, it is not necessary to put what type of data will be stored in the variable. Here is an example:

total_Python = 10

In this example of a programming variable, a numeric variable is presented and the value it stores is the integer 10. However, we could change the value to text or decimal numbers and it will still be displayed correctly.

Well, we have reached the end of today’s article and surely you have seen that learning what a variable is in programming is easier than it seems at first.

We know that, at first glance, all the numbers, letters and symbols of web programming may make you feel a little overwhelmed, but now that you know what a variable is in programming, you’ve taken the first step in starting your career as a programmer.

As you dig deeper into your knowledge, you’ll be able to create amazing projects. When the time comes, you can use this Wireframe UX template for iOS and Android. Just remember that each programming language has its own rules, despite having several similarities between them.

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