为什么Java主要使用变长参数列表？ [英] Why doesn't Java's main use a variable length argument list?

问题描述

我对Java main 声明的语法有疑问：

I have a question about the syntax of the Java main declaration:

public static void main (String[] args)

因为你可以传递一个可变数量的调用main函数时的字符串，不应该是变量长度参数列表而不是数组吗？为什么使用字符串参数列表对此方法进行命令行调用甚至可以工作？ （除非有幕后处理用字符串列表构建一个数组，然后将该数组传递给main方法......？）主要声明不应该更像这样......？ -

Since you can pass a variable number of Strings when invoking the main function, shouldn't this be a variable length argument list rather than an array? Why would a command-line invocation of this method with a list of string parameters even work? (Unless there is behind-the-scenes processing that builds an array with the list of strings and then passes that array to the main method...?) Shouldn't the main declaration be something more like this...? -

public static void main(String... args) 

推荐答案

main（String ... args）和 main（String [] args）实际上是一回事：你得到的是一个 String 数组。 varargs只是调用者的语法糖。

main(String... args) and main (String[] args) are effectively the same thing: What you're getting is a String array. The varargs is just syntactic sugar for the caller.

我想你从来没有从代码中调用 main（），当引入varargs时，它没有被改装。

I guess as you never call main() from code, it wasn't retrofitted when varargs were introduced.

编辑：实际上，刮开最后一句话。 main（String ... args）当然是完全有效的语法。这两种风格完全可以互换。这很好用：

Edit: Actually, scratch that last sentence. main(String... args) is perfectly valid syntax, of course. The two styles are completely interchangeable. This works just fine:

public class Test {

    public static void main(String... args) {
        System.out.println("Hello World");
    }

}

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