Java Type Conversion Rules Explained

The rules for type conversion in Java are as follows:

1. Automatic type conversion: When the range of one data type is smaller than another data type, the system will automatically convert the smaller range data type to the larger range data type. For example, an int type can be automatically converted to a double type.
2. Type casting: When there is a need to convert a data type with a large range to a data type with a smaller range, type casting is required. Type casting may result in data loss or overflow, so caution is advised when using it.
3. Rules for type conversion: Basic data types can be converted between each other, but one must be mindful of data range issues. Type conversion among objects typically requires the use of a type conversion operator. Subclass objects can be directly assigned to superclass reference variables, but when a superclass object is assigned to a subclass reference variable, a forced type conversion is necessary.
4. Before performing type conversion, it is important to consider the data’s precision and range to avoid data loss or overflow issues. Additionally, when converting object types, it is necessary to ensure that there is an inheritance or implementation relationship between the objects, otherwise it can result in a type conversion exception.