在Java中定义一个字符串数组

In java we can define main() method as both these ways.

在java中，我们可以将main()方法定义为这两种方式。

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

。

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

Both method takes array of String arguments. Now consider following scenario.

这两种方法都接受字符串参数数组。现在考虑以下场景。

    String[] arr=new String[10]; // valid
    String... arr=new String[10];// invalid

Java never allows to create an array like this wayString... arr=new String[10];. But in above method implementation java allows to do so. My question is how java achieve this two different behavior for two scenarios?

Java从不允许创建这样的wayString数组…[10];arr =新字符串。但是在上面的方法实现中，java允许这样做。我的问题是java如何在两个场景中实现这两个不同的行为?

4 个解决方案

#1

...

is a syntax for method arguments and not for variable definitions. The name of this notation is varargs, which is self explanatory i.e variable number of arguments.

是方法参数的语法，而不是变量定义的语法。这个符号的名称是varargs，它是自解释的i。变量数目。

#2

Variable argument or varargs(...) in Java used to write more flexible methods which can accept as many argument as you need not for initialization.

在Java中，变量参数或varargs(…)用于编写更灵活的方法，可以接受尽可能多的参数，而不需要初始化。

#3

... refers to varargs and its main intention to make method more readable.

…是指varargs及其主要意图使方法更易读。

void method(String... args) {

}

can be called as

可以被称为

method("a"); OR method("a", "b"); OR method("a", "b", "c");

方法(“a”);或方法(“a”、“b”);或方法(“a”、“b”、“c”);

I see no point in using it in variable declaration, we can't do much with

我认为在变量声明中使用它没有意义，我们做不了太多。

String... a = {"a", "b"}

An array can anyways be declared with dynamic size

数组无论如何都可以用动态大小声明

String[] arr = {"a"};

或

String[] arr = {"a", "b"};

#4

You can use varargs in main because a method declared with varargs (...) is bytecode compatible with a declaration of a method with an array argument (for backwards compatibility). That does not mean that the same syntax is allowed for type declarations.

您可以主要地使用varargs，因为使用varargs(…)声明的方法与使用数组参数的方法声明兼容(为了向后兼容)。这并不意味着类型声明允许使用相同的语法。

#1

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