Java Learning Note Note--5, identifiers

1, the concept of identifiers

Identifiers are used to name classes, objects, methods, variables, interfaces, and custom data types.

2, the composition of identifiers

,   identifiers can be letters, numbers, underscores ( _ $ @ , % Other special characters, such as spaces, cannot begin with a number.

2. identifiers cannot be java keywords and reserved words ( java reserved keywords, in future upgrade versions have may be a keyword), but can contain keywords and reserved words.

3. Identifiers are strictly case-sensitive. So nirvana, be sure to distinguish between Chu Imooc and IMOOC is two different identifiers Oh!

4, the name of the identifier is best to reflect its role, to be known.

5. Variable name = First character + remainder

First Character: letters, underscores, ' $ ' symbols

The rest of the section: numbers, Letters, underline, ' $ '

3. Naming conventions

1. Variable name

You should avoid keywords

2. Variable name

Camel - compliant hump naming method

If the name consists of multiple words, start with a second word and capitalize the first letter

3. Variable name

Simple and straightforward representation of the function of the variable, first letter lowercase

Java Learning Note Note--5, identifiers