Providing a copy of the content is similar to using "passbyvalue."
提供内容的一个副本与使用“通过值传递(pass by value)”很相似。
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With passbyvalue, any change to the parameter is not reflected in the calling routine. Those who have used passby reference will probably find this confusing.
The Object Request Broker (ORB) passby reference option determines if passby reference or passbyvalue semantics should be used when handling parameter objects involved in an EJB request.