swift - var Double 类型 swift 崩溃

Question

我正在制作一个计算器应用程序，当我得到一个很大的数字时它会崩溃。这是代码。

var accumulator: Double = 0.0
 func updateDisplay() {
    // If the value is an integer, don't show a decimal point
     let iAcc = Int(accumulator)


    if accumulator - Double(iAcc) == 0 {
      numField.text = "\(iAcc)"

    } else {

        numField.text = "\(accumulator)"
    }
}

这里是错误

fatal error: floating point value can not be converted to Int because it is greater than Int.max

如果有人能提供帮助那就太好了!

Answer 1

您可以轻松地使用此扩展来防止崩溃:

extension Double {
    // If you don't want your code crash on each overflow, use this function that operates on optionals
    // E.g.: Int(Double(Int.max) + 1) will crash:
    // fatal error: floating point value can not be converted to Int because it is greater than Int.max
    func toInt() -> Int? {
        if self > Double(Int.min) && self < Double(Int.max) {
            return Int(self)
        } else {
            return nil
        }
    }
}

因此，您的代码将是:

...
let iAcc = accumulator.toInt()
...