英文:
Params in method, Object... VS Object[] , are these two have the same function?
问题
我有一个类似下面的方法：
public IndexRequest source(XContentType xContentType, Object... source) {
// 一些处理
}
我知道如何使用它：
new IndexRequest().source(XContentType.JSON, "field", "baz", "fox"));
现在，我想要像下面这样使用它：
List<String> list = new ArrayList(3);
list.add("field");
list.add("baz");
list.add("fox");
new IndexRequest().source(XContentType.JSON, list));
然后，我发现它已经通过了编译器。但我不确定这个函数是否正确可用...
我能不能使用 Object[] 替代 Object...？
英文:
I have a method like followed:
public IndexRequest source(XContentType xContentType, Object... source) {
// some process
}
And I kown how to use it:
new IndexRequest().source(XContentType.JSON, "field", "baz", "fox"));
Now, I want to use it like this one:
List<String> list = new ArrayList(3);
list.add("field");
list.add("baz");
list.add("fox");
new IndexRequest().source(XContentType.JSON, list));
And then, I find it has passed the Compiler. But I don't know the function is right to be used...
Can I use Object[] instead of Object...
答案1
得分: 2
有列表和数组之间存在差异。最简单的方法是执行以下操作（将列表转换为数组，注意"toArray"方法）：
List<String> list = new ArrayList(3);
list.add("field");
list.add("baz");
list.add("fox");
new IndexRequest().source(XContentType.JSON, list.toArray()));
英文:
There is a difference between a list and an array. The simplest way would be to do the following (converting the list to an array note the "toArray" method):
List<String> list = new ArrayList(3);
list.add("field");
list.add("baz");
list.add("fox");
new IndexRequest().source(XContentType.JSON, list.toArray()));
答案2
得分: 0
public IndexRequest source(XContentType xContentType, Object... source)
在上面的代码片段中，`Object... source` 表示一个对象数组，但也肯定会接受单个对象，这是因为在内部，JVM 会将该对象添加到一个数组中。
在类似的情况下，当您将一个列表传递给该方法时，它会将该列表放入一个名为 `source` 的数组中，因此编译器不会抛出错误。
英文:
public IndexRequest source(XContentType xContentType, Object... source)
In the above snippet, Object... source refers to an Object array, but will surely accept a single object also, this is because internally, JVM will add that object to an array.
On similar lines, when you pass a list to the method, it puts that list into an array named source, because of which the compiler did not throw an error.
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