Java Tokens

Java Tokens

The smallest individual and logical unit of the java statements are called tokens. In Java there are five types of tokens used. These tokens are -

1. Reserved keywords

2. Identifiers

3. Literals

4. Operators

5. Separators

1. Reserved keywords

Keywords are the reserved words which are enlisted as below-

2. Identifiers                                             

Identifiers are the kind of tokens defined by the programmer. They are used for naming the classes, methods, objects, variables, interfaces and packages in the program.

Following are the rules to be followed for the identifiers-

1. The identifiers can be written using alphabets, digits, underscore and dollar sign.

2. They should not contain any other special character within them.

3. There should not be a space within them.

4. The identifier must not start with a digit, it should always start with alphabet.

5. The identifiers are case-sensitive. For example -

int a; int A;

In above code a and A are treated as two different identifiers.

6. The identifiers can be of any length.

3. Literals

Literals are the kind of variables that store the sequence of characters for representing the constant values. Five types of literals are -

1. Integer literal

2. Floating point literal

3. Boolean literal

4. Character literal

5. String literal

As the name suggests the corresponding data type constants can be stored within these literals.

4. Operators

Operators are the symbols used in the expression for evaluating them.

5. Separators

For dividing the group of code and arranging them systematically certain symbols are used, which are known as separators. Following table describes various separators.