Why do we need to force transfer after instanceof?
When using the instanceof operator to check the type of an object, if the result is true, it means that the object is an instance of the specified type. However, the compiler does not automatically convert the object to the specified type, so a cast is required. Casting is the operation of converting an object from one type to another. After using the instanceof operator, if you determine that the object is an instance of the specified type and want to operate with that type, you need to perform cast type conversion.
Operating system for this tutorial: Windows 10 system, Dell G3 computer.
When using the instanceof operator to check the type of an object, if the result is true, it means that the object is an instance of the specified type. However, the compiler does not automatically convert the object to the specified type, so a cast is required.
Coercion is the operation of converting an object from one type to another. After using the instanceof operator, if you determine that the object is an instance of a specified type and want to operate on that type, you need to perform a cast.
The syntax of forced type conversion is as follows:
1 |
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Among them, Type represents the target type, variable represents the variable to be assigned, and object represents the object to be converted.
It should be noted that cast type conversion may cause type mismatch errors, so when performing cast type conversion, you should ensure that the actual type of the object is compatible with the target type, otherwise it may cause a runtime exception. .
In addition, try to avoid frequent use of forced type conversion, because it may destroy the encapsulation and security of the type. Priority should be given to using object-oriented features such as polymorphism and interfaces to implement code logic. Casting should only be used when type conversion is absolutely necessary.
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