What is the difference between an int, a long, a double and a decimal in Java?

There are eight primitive datatypes supported by Java. Primitive datatypes are predefined by the language and named by a keyword. int Int data type is a 32-bit signed two's complement integer. Minimum value is - 2,147,483,648 (-2^31) Maximum value is 2,147,483,647(inclusive) (2^31 -1) Integer is generally used as the default data type for integral values unless there is a concern about memory. The default value is 0 Example: int a = 100000, int b = -200000 long Long data type is a 64-bit signed two's complement integer Minimum value is -9,223,372,036,854,775,808(-2^63) Maximum value is 9,223,372,036,854,775,807 (inclusive)(2^63 -1) This type is used when a wider range than int is needed Default value is 0L Example: long a = 100000L, long b = -200000L double double data type is a double-precision 64-bit IEEE 754 floating point This data type is generally used as the default data type for decimal values, generally the default choice Double data type should never be used for precise values such as currency Default value is 0.0d Example: double d1 = 123.4 read less