Swift 2.0 substringwithrange

Question

I've Xcode 7 gm, with swift 2.0 what is equivalent espression of:

Let myNSString = "full text container"
myNSString.substringWithRange(NSRange(location: 0, length: 3))

With new string class?

Answer 1

Try this:

let myString = "full text container"
myString[myString.startIndex..<myString.startIndex.advancedBy(3)]

Answer 2

You can use these extensions:

Swift 2

extension String
{   
    func substringWithRange(start: Int, end: Int) -> String
    {
        if (start < 0 || start > self.characters.count)
        {
            print("start index \(start) out of bounds")
            return ""
        }
        else if end < 0 || end > self.characters.count
        {
            print("end index \(end) out of bounds")
            return ""
        }
        let range = Range(start: self.startIndex.advancedBy(start), end: self.startIndex.advancedBy(end))
        return self.substringWithRange(range)
    }

    func substringWithRange(start: Int, location: Int) -> String
    {
        if (start < 0 || start > self.characters.count)
        {
            print("start index \(start) out of bounds")
            return ""
        }
        else if location < 0 || start + location > self.characters.count
        {
            print("end index \(start + location) out of bounds")
            return ""
        }
        let range = Range(start: self.startIndex.advancedBy(start), end: self.startIndex.advancedBy(start + location))
        return self.substringWithRange(range)
    }
}

Swift 3

extension String
{
    func substring(start: Int, end: Int) -> String
    {
        if (start < 0 || start > self.characters.count)
        {
            print("start index \(start) out of bounds")
            return ""
        }
        else if end < 0 || end > self.characters.count
        {
            print("end index \(end) out of bounds")
            return ""
        }
        let startIndex = self.characters.index(self.startIndex, offsetBy: start)
        let endIndex = self.characters.index(self.startIndex, offsetBy: end)
        let range = startIndex..<endIndex

        return self.substring(with: range)
    }

    func substring(start: Int, location: Int) -> String
    {
        if (start < 0 || start > self.characters.count)
        {
            print("start index \(start) out of bounds")
            return ""
        }
        else if location < 0 || start + location > self.characters.count
        {
            print("end index \(start + location) out of bounds")
            return ""
        }
        let startIndex = self.characters.index(self.startIndex, offsetBy: start)
        let endIndex = self.characters.index(self.startIndex, offsetBy: start + location)
        let range = startIndex..<endIndex

        return self.substring(with: range)
    }
}

And it will be more simple:

let substring = myNSString.substringWithRange(0, location: 3)