单元素括号表达式/元组与括号的常见用法 [英] Single-element parethesized expressions/tuples vs common use of parentheses

问题描述

对不起，如果这是微不足道的 - 我是 swift 的新手，实际上我只看了几分钟的语言指南+参考.

Sorry if this is trivial - I am so new to swift, actually I have only looked at the language guide+reference for a few minutes.

据我所知，像 (2,3) 这样的括号表达式用于构造元组，而 (2) 是类型为单元素的元组(Int).

As far as I understand a parenthesized expression like (2,3) is used to construct a tuple, and (2) is a single-element tuple of type (Int).

但是，在表达式 (2+4)*5 中通常使用诸如 (2+4) 之类的括号会发生什么?这仍然是 (Int) 类型的元组乘以 Int 吗?

But then what happens with common use of parentheses like (2+4) in expression (2+4)*5? Is this still a tuple of type (Int) multiplied by an Int?

推荐答案

来自 :

From Types in the Swift book:

如果括号内只有一个元素，则类型为只是该元素的类型.例如，(Int) 的类型是Int，不是(Int).

If there is only one element inside the parentheses, the type is simply the type of that element. For example, the type of (Int) is Int, not (Int).

所以(2)或(2+4)的类型就是Int，*> 在 (2+4)*5 中是只是整数乘法.

So the type of (2) or (2+4) is simply Int, and the * in (2+4)*5 is just integer multiplication.

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