Swift 2未使用的持续警告 [英] Swift 2 unused constant warning

问题描述

我收到一条警告，说我的常量未被使用：

I am getting a warning saying my constant is unused:

永远不会使用不可变值'myConst'的初始化;考虑将作业替换为'_'或将其删除

Initialization of immutable value 'myConst' was never used; consider replacing with assignment to '_' or removing it

if someVal["value"] != nil {
    let myConst = someVal["value"]
}

那么什么将重命名让myConst = someVal [value] 进入 _ myConst = someVal [value] do / mean？

So what will renaming let myConst = someVal["value"] into _ myConst = someVal["value"] do/mean?

推荐答案

你不是用 _ 替换let ，但是你要用它替换变量名。如果变量没有在代码中的任何地方使用，则它是无关紧要的，因此该行可以写成：

You're not replacing let with _, but you're replacing the variable name with it. If the variable isn't used anywhere in the code it's irrelevant so the line can be written like:

_ = someVal["value"]

如果你想在某个地方使用它，你需要一个名字，以便以后引用它。但是当你不使用它时，写 _ 要容易得多......

If you want to use it somewhere you need a name for it to reference it later on. But when you don't use it writing _ is a lot easier ...

这篇关于Swift 2未使用的持续警告的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！