Java identifers

 

Identifiers

All Java variables must be identified with unique names.

For example -different people have different names

These unique names are called identifiers.

Identifiers can be short names (like a and b) or more specific names (program,code ,techySowmi).

Note: It is suggested to use specific names in order to create understandable and maintainable code:

example

public class Main {

public static void main(String[] args) {

// Good

String howAreYou= “fine”;

int totalMarks = 90;

// OK, but not so easy to understand what a ,b actually is

String a = “fine”;

int b=90;

System.out.println(howAreYou);

System.out.println(a);

System.out.println(b);

System.out.println(totalMarks);

}

}

Output-

fine

fine

90

90

The general rules for naming variables are:

• Names can contain letters, digits, underscores, and dollar signs

• Names must begin with a letter

• Names should start with a lowercase letter and it cannot contain whitespace

• Names can also begin with $ and _ (but we will not use it in this tutorial)

• Names are case sensitive ("myVar" and "myvar" are different variables)

• Reserved words (like Java keywords, such as int or boolean) cannot be used as names