Java Tokens
(Tap the post to see more)
Java tokens are the smallest
individual units in a program
Keywords:
•
These are the pre-defined reserved words of any programming language.
•
Each keyword has a special meaning.
•
It is always written in lowercase.
e.g. class, while,
for, interface, abstract…..
Identifier:
•
Identifiers are used to name a
variable, constant, function, class, and array.
•
It is usually defined by the user.
•
It uses letters, underscores, or a
dollar sign as the first character.
•
Identifier names must be different from
the reserved keywords.
There are some rules to declare identifiers are:
❑ The
first letter of an identifier must be a letter, underscore or a dollar sign. It
cannot start with digits but may contain digits.
❑ The
whitespace cannot be included in the identifier.
❑ Identifiers
are case sensitive.
•
Some
valid identifiers are:
•
PhoneNumber
•
PRICE
•
radius
•
a
•
a1
Invalid Identifiers
•
1sum
•
Sum 1
Literals:
•
literal is a notation that represents a
fixed value (constant) in the source code.
•
It can be categorized as an integer
literal, string literal, Boolean literal, etc.
•
It is defined by the programmer.
•
Once it has been defined, it cannot be
changed.
Java provides five types of literals are as follows:
●
Integer
●
Floating Point
●
Character
●
String
● Boolean
Operators:
•
operators are the special symbol to
perform mathematical operations or logical manipulations
•
Java provides different types of
operators that can be classified according to the functionality they provide.
There are eight types
of operators in Java, are as follows:
•
Arithmetic Operators
•
Assignment Operators
•
Relational Operators
•
Unary Operators
•
Logical Operators
•
Ternary Operators
•
Bitwise Operators
• Shift Operators
Separators:
•
The separators in Java is also known
as punctuators.
•
separators in Java, are as follows:
•
; (semicolon)
•
, (comma)
•
. (dot)
•
{ } (braces)
•
[ ] (bracket)
•
( ) (parenthesis)
Comments:
Comments are used to describe the program
•
Single Line Comment (// Double Slash)
// This is an example
program to add two numbers
// Java program to
illustrate the addition of numbers
•
Multi-line Comment (/* */)
/*This is an example
program to
add two numbers */
Constants
❑ Constants
are the fixed values that never change during the execution of a program.
❑ Various
types of constants:
⮚ Integer
Constants
▪
An integer constant is nothing but a value
consisting of digits or numbers
▪
Example : 111, 1234
⮚ Floating point Constants
▪
constants that contain a decimal point or a
fraction value.
▪
Example: 223.14, 400.054
⮚ Character
Constants
▪
A character constant contains only a single
character enclosed within a single quote (‘ ').
▪
Example: ‘A’ , ‘m’, ‘9’
⮚ String
Constants
▪
A string constant contains a sequence
of characters enclosed within double quotes (“ “).
▪
Example: “Welcome”,
“Hello”
Labels: Java
0 Comments:
Post a Comment
Subscribe to Post Comments [Atom]
<< Home