Data type conversions: advanced to low-level conversion possible problems and methods of obtaining different precision

The basic data types are from low to Advanced: (Byte,short,char)--int--long- - float -- Double

PS: The "level" here refers to the size of the range that represents the value.

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For a double-precision real class,Doublevalue () can get its corresponding double-precision real variable, and intvalue () can get its corresponding integer variable.

This method can be used when fetching 123.45 (long) and 123 (int) of different types.

You also need to consider the question that the value should be in the range of two types, such as between 1 and 100, which must be in double and int

Data type conversions: advanced to low-level conversion possible problems and methods of obtaining different precision