快捷运算符"*"在两个Int上引发错误

问题描述

我在这里有一个非常奇怪的错误，我已经搜索了所有内容，并尝试了所有建议.没有工作.

I have a very odd error here and i've searched all around and i have tried all the suggestions. None work.

scrollView.contentSize.height = 325 * globals.defaults.integer(forKey: "numCards")

WTF迅捷！为什么不?我一直乘以Ints.这两个 ARE 两个Ints. globals.defaults只是UserDefaults.standard的一个实例.我每次都尝试使用相同的错误进行以下操作.

WTF Swift! Why not? I multiply Ints all the time. These ARE two Ints. globals.defaults is just an instance of UserDefaults.standard. I have tried the following with the same error each time.

325 * Int(globals.defaults.integer(forKey: "numCards")   //NOPE

Int(325) * Int(globals.defaults.integer(forKey: "numCards"))  //NOPE

if let h = globals.defaults.integer(forKey: "numCards"){
    325 * h  //NOPE, and 'Initializer for conditional binding must have optional type, not Int'
}

let h = globals.defaults.integer(forKey: "numCards") as! Int
325 * h //NOPE, and 'Forced cast of Int of same type as no affect'

325 * 2 //YES!  But no shit...

所有这些尝试"似乎都是在浪费时间，因为我知道这两个事实都是Ints ...而且我是正确的.请指教.谢谢！

All of those "attempts" seemed like a waste of time as i know for a fact both of these are Ints...and i was correct. Please advise. Thanks!

推荐答案

该错误具有误导性.问题实际上是试图将Int值分配给CGFloat变量.

The error is misleading. The problem is actually the attempt to assign an Int value to a CGFloat variable.

这将起作用:

scrollView.contentSize.height = CGFloat(325 * globals.defaults.integer(forKey: "numCards"))

产生误导性错误的原因(由于下面的注释中的Daniel Hall)是由于编译器选择了*函数，该函数由于需要返回值而返回了CGFloat.该功能需要两个CGFloat参数.由于提供的两个参数是Int而不是CGFloat，因此编译器提供了误导性错误:

The cause of the misleading error (thanks to Daniel Hall in the comments below) is due to the compiler choosing the * function that returns a CGFloat due to the return value needed. This same function expects two CGFloat parameters. Since the two arguments being provided are Int instead of CGFloat, the compiler provides the misleading error:

如果错误更像是这样，那就太好了

It would be nice if the error was more like:

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