#Coding || Java Tokens

java tokens

 

A java program is basically a collection of classes .A class is defined by a set of declaration statements and methods containing executable statements. Most statements contain expressions, which describe the actions carried out on data. Smallest individual units in a program are known as tokens.

Basically,A java program is a collection of tokens, comments and white spaces.Java language includes five types of tokens. They are:-

• Reserved Keywords                                                
• Identifiers
• Literals
• Operators
• Separators.

Java Character Set

The smallest units of Java language are the characters used to write Java tokens. These characters an defined by the Unicode character set, an emerging standard that tries to create characters for a large numbe of scripts worldwide.

The Unicode is a 16-bit character coding system and currently supports more than 34,000 define characters derived from 24 languages from America, Europe, Middle East, Africa and Asia (including India). However, most of us use only the basic ASCII characters, which include letters, digits and punctuation marks, used in normal English. 

Keywords

*Keywords are an essential part of a language definition. They implement specific features of the language .

*Java language has reserved 50 words as keywords.

* Keyword have specific meaning in java,we cannot use them as names for variables,classes,methods and so on. 

*All Keywords are to be written in lower case letters. 

*Java is case sensitive, one can use these words as identifiers by changing one or more letters to  upper case. 

Java Keywords 

abstract                 byte                case                   do                        class                extends              for const                    double             continue             finally                interface           default           float  return                  super                throw                  void                    final                goto           instanceof   native if             protected           static               synchronize        transient           while          import         long                   private             short                 switch                  throws          volatile        now   public              strictip                 this                     try

Note: We should also not attempt to use the boolean values true and false or null as names in our programs.