java java中的实用函数是什么意思？它与静态有什么关系？
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what do you mean by utility functions in java?how it is related to Static?
提问by sanath sanu
hi what is the actual meaning of utility function in java?
嗨，java中效用函数的实际含义是什么？
回答by Chris K
The term utility function was used by Joshua Blochin the book Effective Javato describe the methods on classes such as Arrays, Objectsand Math.
Joshua Bloch在Effective Java一书中使用了效用函数这个术语来描述诸如数组、对象和数学之类的类的方法。
The approach predates Java, and is defined by Wikipedia - Utility Classas a set of methods that perform common, often reused functions. I would go on to also point out that the functions tend to require no Object level state, that is they tend to be global functions. And that is why, in Java they tend to become implemented as static methods on a container class. As that way there is no need to instantiate the class first, and it implies through convention that the method should not have any side effects. Of course counter examples of this probably exist, but not to my knowledge within the Java Core libraries.
该方法早于 Java，并由Wikipedia - Utility Class定义为一组执行常见、经常重用功能的方法。我还要继续指出，函数往往不需要对象级别的状态，也就是说，它们往往是全局函数。这就是为什么在 Java 中，它们倾向于在容器类上实现为静态方法。这样就不需要首先实例化类，并且通过约定暗示该方法不应该有任何副作用。当然，这方面的反例可能存在，但据我所知在 Java 核心库中并不存在。
