A Java literal is nothing but a constant value e.g 100, "hello", 20.30 are some valid Java literals.
Here is some Java integer literals example:
int i = 100; int binary = 0b1010; int dash = 123_456_789;
Beginning with JDK 7, we can have integer literals using binary. To do so, prefix the value with 0b or 0B:
int x = 0b1010;
It specifies the decimal value 10 using a binary literal.
Integer literal can have one or more underscores and it makes easier to read large integer literals. For example:
int x = 100_109_200;
When compiled all underscore will ignored and the actual value of x will be 100109200.
A Java boolean value can have true or false only, nothing else. For example:
boolean isValid = true; boolean isRedColor = false;
Character literals are enclosed in single quotation marks for example 'a', 'A', '9', '+', '_', and '~'.
char c = 'A';
String literals are enclosed between a pair of double quotes:
String str = "Hello Java!";
It is a whole number component followed by a decimal point followed by a fractional component. For example 98.21, 10.0.
A floating-point number plus a suffix that specifies a power of 10 by which the number is to be multiplied, for example 6.02E21, 27159E–05 are also a valid floating point number. The exponent is indicated by an E or e followed by a decimal number.