如何在Swift 2.0中将字符插入字符串？

Question

此函数接受Int like 324543并返回类似"$ 3245.43"的字符串

我的尝试在下面,但Swift 2不喜欢 atIndex: 0

我如何将字符插入字符串呢？

func stylizeCents (cent: Int) -> String {
    var styledCents = String(cent)
    let dollarSign : Character = "$"
    let dot : Character = "."
    let count = styledCents.characters.count
    styledCents.insert(dollarSign, atIndex: 0) // error
    styledCents.insert(dot, atIndex: count-1) // error
}

Answer 1

这似乎已经在这个答案中解决了.

Swift 2.0

您可以使用字符串扩展名:

extension String {
    func insert(string:String,ind:Int) -> String {
        return  String(self.characters.prefix(ind)) + string + String(self.characters.suffix(self.characters.count-ind))
    }
}

用过:

var url = "http://www.website.com"
url = url.insert("s", ind: 4) // outputs https://www.website.com