What is a java identifier
An identifier is a sequence of characters that names a class, interface, method, variable, etc.
Identifier composition rules:
1, English upper and lower case letters
2, numbers
3, $ and _
Notes:
1. It cannot start with a number
2. It cannot be a keyword in java
3. Distinguish Case
Common naming rules:
A. Package: all lowercase
Single-level package: lowercase
Example:
liuyi,com
Multi-level packages: lowercase, separated by .
Example:
cn.itcast,com.baidu
B. Class or interface
One word: capitalize the first letter of each word
Example:
Student,Demo
Multiple words: capitalize the first letter of each word
Example:
HelloWorld,StudentName
C. Method or variable
One word: the first letter is lowercase
Example:
name,main
Multiple words: starting from the second word, The first letter of each word is capitalized
Example:
studentAge,showAllNames()
D.Constant
All capital letters
One word: capital
Example:
PI
Multiple words: capitalized and separated by _
Example:
STUDENT_MAX_AGE
Recommended tutorial:Java tutorial
The above is the detailed content of what is identifier in java. For more information, please follow other related articles on the PHP Chinese website!