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FrEqDe
Asked: 2020-06-14 17:42:01 +0800 CST 2020-06-14 17:42:01 +0800 CST

What is the convention for writing variables in Java?

  • 772

In the case of variable names with a single word, it is normal to write them in the following way:

int entero;
double doble;
String cadena;

But for the case of variables that use two words, how should they be written? I have only used two forms:

  • Option 1:

    int numero_entero;

    double numero_doble;

  • Option 2:

    int numeroEntero;

    double numeroDoble;

I have also noticed that some variables that the Java libraries have are written in uppercase and separated by _ :

Foo.ANCHURA_MAXIMA;
Foo.ANCHURA_MINIMA;
java

2 Answers

  1. Best Answer

    Naming conventions make programs more understandable by making them easier to read. They can also provide information about the function of the identifier, such as whether it is a constant, a package, or a class, which can be helpful in understanding your code.

    The Java documentation outlines its naming convention:

    Paquetes

    The prefix of a unique package name is always written in lowercase ASCII letters and should be one of the top-level domain names, currently com, edu, gov, mil, net, org, or one of the two-letter codes in English identifying countries as specified in ISO 3166, 1981 .

    Subsequent components of the package name vary according to an organization's internal naming conventions. Such conventions might specify that certain directory name components are division, department, project, machine, or login names.

    com.sun.eng
com.apple.quicktime.v2
edu.cmu.cs.bovik.cheese

    Clases

    Class names must be nouns . If there is more than one word, the first letter of each word is capitalized. Try to keep your class names simple and descriptive. Use complete words: avoid acronyms and abbreviations (unless the abbreviation is used much more than the long form, such as URL or HTML).

    class Raster; 
class ImageSprite;

    Interfaces

    Interface names must be written with each first letter capitalized, like class names.

    interface RasterDelegate; 
interface Storing;

    Métodos

    Method names must be verbs. The first letter is always lowercase and if there are several words, the first letters of each internal word in uppercase.

    run(); 
runFast(); 
getBackground();

    Variables

    Except for variables, all instances, classes, and class constants are case sensitive with a lowercase first letter. Internal words start with capital letters. Variable names must not start with underscores _or dollar signs $, although both are allowed.

    Variable names should be short but meaningful. The choice of a variable name should be mnemonic, that is, designed to indicate to the casual observer the intended use. One-character variable names should be avoided, except for "throwaway" temporary variables. Common names for temporary variables are:

    i, j, k, m, and nfor integers;

    c, d, and efor characters.

    int     i;
char    c;
float   myWidth;

    Constantes

    The names of variables declared as class constants and of ANSI constants must be all uppercase with words separated by underscores (" _") . (ANSI constants should be avoided, for ease of debugging.)

    static final int MIN_WIDTH = 4;
static final int MAX_WIDTH = 999;
static final int GET_THE_CPU = 1;

    However you can use another convention. It is recommended that it be one of the standardized ones in the programming community and that it be uniform , that is, that you use the same naming convention in all your code.

    • 17

  2. As a general rule:

    For classes and variables:

    1. Valid characters: letters, $, _, numbers.
    2. Identifiers should never start with numbers
    3. Identifiers can start with symbols $and_
    4. Do not use JAVA reserved words

    Lessons:

    1. Use of convention UperCamelCase (first letter capitalized, the rest of the words begin in capital letters.)

      public class MiClase{
}

    Variables:

    1. Use of convention lowerCamelCase(first letter lowercase, the rest of the words begin in uppercase.) p/e: fullname

      String nombreCompleto;
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