Tokens

• Tokens are smallest unit of java program.
• Tokens are classifed into 1) Keywords 2) Seperators 3) Identifiers 4) Literles

  1) Keywords

• Keywords are predefine words in java.
• It is also known as reserved words in java.
• Java compiler will be aware of the keywords.

  How identifies keywords ?

• All keywords are in lower case.
• e.g. public,class,static

2) Separators

e.g.

{
    ;   ,   (   )   "  "    :   '  '
}

3) Literals

• Literals are the types of values used in java program.
  
• i) Numbers
  • integer - 10,1,100,15
  • float - 10.1,30.4,33.2
    
• ii) Characters
  • ‘a’,’b’,’c’,’A’,’B’,’C’
  • ‘a’ != ‘A’
  • 97 != 65 (ASCII value)
  • ASCII value - byte code
    
• iii) String
  • “Hello”
    
• iv) Boolean
  • true/false
    

Note

• Java is casesensitive.

4) Identifires

• Identifire is name given by the programmer to the elements of java.
• e.g. class name, variable name, method name