ECMAScript 文档中的 SpreadElement 是什么?和 MDN 上的 Spread 语法一样吗?

The term "spread operator" is kind of an "umbrella term" that refers to various syntactic constructs in ES6 which all look like ...x. MDN does the same.

但是，这是误导，因为 ... 不是运算符(至少在 ECMAScript 规范使用术语运算符"的意义上不是).它不会生成可用于进一步计算的值.我宁愿将它与其他标点符号进行比较，例如 , 或 ; (它们也有点相关，但在不同的上下文中具有不同的含义).

However, this is misguiding, because ... is not an operator (at least not in the sense the ECMAScript spec uses the term "operator"). It doesn't generate a value that can be used in further computations. I'd rather compare it to other punctuators, such as , or ; (which are also kind of related but have different meaning in different context).

术语扩展运算符"可以指:

The term "spread operator" could refer to:

• 传播元素，var arr = [a, b, ...c];:展开元素将可迭代(c)扩展为新数组.它相当于 [a,b].concat(c).

• Spread element, var arr = [a, b, ...c];: The spread element expands the iterable (c) into the new array. It's equivalent to something like [a,b].concat(c).

休息元素，[a, b, ...c] = arr;^†:内部解构，... 构造具有相反的效果:它将剩余元素收集 到一个数组中.这里的例子等价于

Rest element, [a, b, ...c] = arr;^†: Inside destructuring, the ... construct has the opposite effect: It collects remaining elements into an array. The example here is equivalent to

a = arr[0];
b = arr[1];
c = arr.slice(2);

(请注意，这只是一个近似值，因为解构适用于任何可迭代的值，而不仅仅是数组)

(note that this only an approximation, because destructuring works on any iterable value, not just arrays)

fun(a, b, ...c):这个构造 在规范中实际上没有名称.但它的工作原理与展开元素非常相似:它将一个可迭代对象扩展为参数列表.
它相当于 func.apply(null, [a, b].concat(c)).

fun(a, b, ...c): This construct doesn't actually have a name in the spec. But it works very similar as spread elements do: It expands an iterable into the list of arguments.
It would be equivalent to func.apply(null, [a, b].concat(c)).

缺乏正式名称可能是人们开始使用spread operator"的原因.我可能会称之为传播论点".

The lack of an official name might be the reason why people started to use "spread operator". I would probably call it "spread argument".