ELEMENTARY PROGRAMMING - Introduction to Java Programming: Comprehensive Version - page 49

2.10.1 Integer Literals
An integer literal can be assigned to an integer variable as long as it can fit into the variable. A
compile error will occur if the literal is too large for the variable to hold. The statement byte
b = 128 , for example, will cause a compile error, because 128 cannot be stored in a variable
of the byte type. (Note that the range for a byte value is from -128 to 127 .)
An integer literal is assumed to be of the int type, whose value is between

2 31 ( 2147483648) and 2 31

1 (2147483647). To denote an integer literal of the long
type, append the letter L or l to it. For example, to write integer 2147483648 in a Java pro-
gram, you have to write it as 2147483648L or 2147483648l , because 2147483648 exceeds
the range for the int value. L is preferred because l (lowercase L ) can easily be confused
with 1 (the digit one).

- - -

Note
By default, an integer literal is a decimal integer number. To denote a binary integer
literal, use a leading 0b or 0B (zero B), to denote an octal integer literal, use a leading
0 (zero), and to denote a hexadecimal integer literal, use a leading 0x or 0X (zero X).
For example,

binary, octal, and hex literals

System.out.println( 0B1111 ); // Displays 15
System.out.println( 07777 ); // Displays 4095
System.out.println( 0XFFFF ); // Displays 65535
Hexadecimal numbers, binary numbers, and octal numbers are introduced in Appendix F.

2.10.2 Floating-Point Literals
Floating-point literals are written with a decimal point. By default, a floating-point literal is
treated as a double type value. For example, 5.0 is considered a double value, not a float
value. You can make a number a float by appending the letter f or F , and you can make
a number a double by appending the letter d or D . For example, you can use 100.2f or
100.2F for a float number, and 100.2d or 100.2D for a double number.

suffix f or F
suffix d or D

Note
The double type values are more accurate than the float type values. For example,
System.out.println( "1.0 / 3.0 is " + 1.0 / 3.0 );

double vs. float

displays 1.0 / 3.0 is 0.3333333333333333

16 digits

System.out.println( "1.0F / 3.0F is " + 1.0F / 3.0F );

displays 1.0F / 3.0F is 0.33333334

8 digits

A float value has 7 to 8 number of significant digits and a double value has 15 to 17 number
of significant digits.

2.10.3 Scientific Notation
Floating-point literals can be written in scientific notation in the form of a 10 b . For example, *

10 2 and for 0.0123456 is 1.23456

the scientific notation for 123.456 is 1.23456 * * 10 - 2 .

A special syntax is used to write scientific notation numbers. For example, 1.23456 * 10 2 is

10 - 2 as 1.23456E-2 . E (or e ) repre-
sents an exponent and can be in either lowercase or uppercase.

written as 1.23456E2 or 1.23456E+2 and 1.23456 *