Literals
Any constant value which can be assigned to the variable is called Literals
Integer type literal:For integral data type we can specify literal value in the following way.
1.Decimal literal (base 10):
example:
int x = 10;
2.Octal form literal (base 8):
example:
int x = 010;
3.Hexadecimal literal (base 16):
example:
int x = 0x0010;
Floating-point literal:For floating data type we can specify literal value only in decimal form and we cannot specify in octal and hexadecimal form.
float f = 123.456; (we get compile time error because JVM by-default considered literals as Double )
float f = 123.456f; (valid because we explicit double into float)
double d = 13.258; (valid)
** By-default every floating point literal is of double type and we cannot assign directly to the float variable.But we can specify floating point literal as float type by suffixed with f or F.
**we can assign integral literal directly to floating point variables but we cannot assign a integral variables with floating point literal.
double d = 10; (valid)
int x = 10.2; (invalid)
boolean literal:The only allowed value for boolean data type are true or false.
boolean b = true; (valid)
boolean b= 10; (invalid because we assign integer value to boolean type)
boolean b= True; (invalid because the value of boolean literals should be in lowercase)
char literal:We can specify char literal as single character within single quotes.
char ch = 'a'; (valid)
char ch = "a"; (invalid because we cannot assign a string literal to char data type)
char ch = 'ab'; (invalid because we can only assign single alphabet character to char data type.)
** We can specify char literal as integral literal which represent unicode value of the character and that integral can be specified either in decimal,octal and hexadecimal forms.But allowed range is 0 to 65535.
char ch = 97; (valid)
char ch = 0777; (valid)
char ch = 0xface; (valid)
** We can represent char literal in Unicode representation which is nothing but '\uxxxx' .
char ch = '\u0062'; (valid)
String literal:Any sequence of character within double quotes is treated as String literal.
String s = "hello world";
NOTE:
1.For integral data type until 1.6 version we can specify literal value in the following ways:
Decimal form,Octal form and Hexadecimal form.
But from 1.7 version onwards we can specify literal value even in Binary form also(allowed digit are 0 & 1):
Literal value should be prefixed with 0b or 0B.
int x = 0b1111;
2.Usage of underscore symbol in numeric literal from 1.7 version onwards we can use underscore(_) symbol
between digit of numeric literal.
double d = 1_23_456.7_8_9;
int x = 123_32_43;