ios - 如何在 swift 3.0 中使用 ""检查条件

Question

1. 我想检查 maxprice 是否等于 ""如果它是 ""那么 maxprice 将变为 maxprice = 0

我的 Json

price = ({
    maxprice = "<null>";
    minprice = "<null>";
});

代码

var Arr = NSArray()

Arr = result.value(forKey: "price") as! NSArray
let max = Arr.value(forKey: "maxprice")

if max == nil {
    self.MaxValue = 0
    self.MinValue = 0
}

else {
    let maxval =  (Arr.object(at: 0) as AnyObject).value(forKey: "maxprice") as! NSNumber
    let min =  (Arr.object(at: 0) as AnyObject).value(forKey: "minprice") as! NSNumber

    self.MaxValue = maxval
    self.MinValue = min
}

Error: Could not cast value of type 'NSNull' (0x102148918) to 'NSNumber' (0x10311c4a8).

Answer 1

您还可以使用 is 检查是否存在空值:

if Arr.value(forKey: "maxprice") is NSNull {
    // do something with null JSON value here
}