如何在没有"Optional"的情况下从plist打印字符串? [英] How to print a string from plist without "Optional"?

问题描述

我从plist中的字典中加载了一个值，但是当我将其打印到控制台时，它会打印:Optional(星期一标题)，而不仅仅是星期一标题".

I load a value from a dictionary in a plist but when I print it to the console, it prints: Optional(Monday Title) rather than just "Monday Title".

如何在打印时摆脱值的Optional()?

How can I get rid of the Optional() of my value when printing?

var plistPath = NSBundle.mainBundle().pathForResource("days", ofType: "plist")
var plistArray = NSArray(contentsOfFile: plistPath!) as NSArray!

    for obj: AnyObject in plistArray {
        if var dicInfo = obj as? NSDictionary {
            let todayTitle: AnyObject? = dicInfo.valueForKey("Title")
            println(todayTitle)
        }
    }    

推荐答案

摆脱Optional的一种方法是使用感叹号:

One way to get rid of the Optional is to use an exclamation point:

println(todayTitle!)

但是，只有在确定存在该值的情况下，才应该这样做.另一种方法是解开包装并使用条件式，如下所示:

However, you should do it only if you are certain that the value is there. Another way is to unwrap and use a conditional, like this:

if let theTitle = todayTitle {
    println(theTitle)
}

将此程序粘贴到 runswiftlang 中进行演示:

Paste this program into runswiftlang for a demo:

let todayTitle : String? = "today"
println(todayTitle)
println(todayTitle!)
if let theTitle = todayTitle {
    println(theTitle)
}

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