IDENTIFIERS IN JAVA

All Java components require names. Name used for classes, methods, interfaces and variables are called Identifier. Identifier must follow some rules. Here are the rules:

• All identifiers must start with either a letter( a to z or A to Z ) or currency character($) or an underscore(_).
• After the first character, an identifier can have any combination of characters.
• A Java keyword cannot be used as an identifier.
• Identifiers in Java are case sensitive, off and Off are two different identifiers.

There are two types of identifiers

• Legal
• Illegal

The following are legal variable names:

• MyVariable
• myvariable
• MYVARIABLE
• x
• i

The following are illegal variable names;

• My Space //Contains a space
• 9pins6s // Begins with a digit
• k+h // The plus sign is not an alphanumeric character testing
• 61-72-83 // The hyphen is not an alphanumeric character