And what it's saying semantically is, using that variable as my placeholder, have it walk through this collection, starting at the first thing, execute that code, then the next thing, execute that code, and so on.

它的语义意思就是，把这个变量应用为我的占位符，用它来遍历这个集合，从第一个元素开始，执行代码，然后下一个元素，再执行代码。

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