What is the difference between Java double and float?

In Java, both double and float are floating-point data types, but they have the following differences:

1. Precision: The precision of a double type is higher than that of a float type, as it can represent a larger range of values and more decimal places. A double type has a length of 64 bits and can represent 15 decimal places, while a float type only has a length of 32 bits and can represent 7 decimal places.
2. Storage size: The storage space required for a double type is double that of a float type. Double type occupies 8 bytes while float type occupies 4 bytes.
3. Literal suffix: In Java, to represent a float type literal, you need to add an “f” or “F” suffix after the number, while for a double type literal you can either write the number directly or add a “d” or “D” suffix.
4. Loss of precision: When performing floating-point arithmetic, float data types are more susceptible to loss of precision compared to double data types. This is because float data types have lower precision and may require rounding during calculations. Therefore, for scenarios that require high precision computations, it is recommended to use double data types.

In general, if higher precision and a larger range of values are needed, the double type can be used; if precision is not a high priority or storage space needs to be saved, the float type can be used.