Swift4.2 字符串空格处理

extension String {
    
    /// 去掉首尾空格
    var removeHeadAndTailSpace:String {
        let whitespace = NSCharacterSet.whitespaces
        return self.trimmingCharacters(in: whitespace)
    }
    
    /// 去掉首尾空格 包括后面的换行 \n
    var removeHeadAndTailSpacePro:String {
        let whitespace = NSCharacterSet.whitespacesAndNewlines
        return self.trimmingCharacters(in: whitespace)
    }
    /// 去掉所有空格
    var removeAllSapce: String {
        return self.replacingOccurrences(of: " ", with: "", options: .literal, range: nil)
    }
    
    /// 去掉首尾空格 后 指定开头空格数
    func beginSpaceNum(num: Int) -> String {
        var beginSpace = ""
        for _ in 0..<num {
            beginSpace += " "
        }
        return beginSpace + self.removeHeadAndTailSpacePro
    }
    /// 字符串是否为空
    static func blank(text: String) -> Bool {
       // let trimmed = text.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceAndNewlineCharacterSet())
        let trimmed = text.trimmingCharacters(in: CharacterSet.whitespacesAndNewlines)
        return trimmed.isEmpty
    }
}