A Java program, similar to programs in other programming languages, It also uses the literals, variables, tokens, data types, etc.
Some of the features are derived from previous high-level programming languages like C, C++, like every programming language, and can have its own predefined keywords.
They can use the identifier to give a unique name and they can use comments to make code understandable.
Java Tokens
Tokens are the smallest units of Java that are used to create Java programs. Tokens can have their own rules to implement. Mainly there are six types of tokens that are used in Java.
- Keyword
- Separator
- Identifier
- Operator
- Literal
- Comment
Keyword
Keywords are the predefined words that can have some special meaning in particular programming.
Keywords can not be reused as a variable or methods or classes in a program. The list of a keyword which is predefined in Java is given below.
throw public instanceof else byte void strictfp native float for if assert throws return int extends case volatile super new package private do boolean transient short interface final catch while switch synchronized this imports double break try static long finally char class continue enum
Separator
Simply separators are known as symbols which are used to give a better structure to the Java program or which helps to write a program in a well-defined manner.
To arrange the Java program code in a well-defined manner we use some special symbols,
- Parentheses () – contains parameter and used to m.
- Braces {} – values automatically initialize arrays.
- Brackets [] – declare the array type
- Comma , – separator
- Semicolon ; – terminates the statement
- Period . – separate the variable and object
- Colon : – for loops
Operators
An operator is a token that allows a programmer to perform a certain operation on data and variables.
Literal
Java program you can assign a literal value to a variable. Literal refers to the constant values that can be changed depending on the program requirement.
The source code representation of the values of primitive data types in a Java program.
Binary Literal
The binary literal express the integral type values in the binary number system. They are introduced in Java 7 specified by adding the prefix 0b or 0B to the number.
byte thisbyte = (byte) 0b00100011;
short thishort = (short) 0b0010011101000111;
The binary literals are useful in a number of programming task to be performed. The literals are frequently used to create numeric arrays.
int[] myarray = {
0b00110011;
0b11001100;
0b00110011;
}
Underscore in Numerical Literal
Underscore is used to make code is more readable. Long numerical literals, a feature has been introduced in Java 7, which allows you to use underscore in numeric literals.
You can use any number of underscore character(_) to break the groups of digits in the long numeric literals.
long myNumber = 232_23234_4343_5445_3434;
long myHex = 0xvBAF_BAB;
- You can use start or end of the numeric literal.
- Use next to the decimal point in the floating point literal.
- Use in front of an F or L suffix in the long numeric literal.
- Place where a string of digits is exacted in the numeric literal
Comment
Comment are special tokens which are used to make more readable code. If any other programme use your program source code for further development he should have to understand the code.
Comments are ignored by Java compiler during the compilation of Java program. They are used to describe the function of the particular part of program.
//this is single line comment
/* this is multiple line comment