Swift String extension

Swift useful string extension (StartsWith & Replace)

extension String {
    
    func startsWith(string: String) -> Bool {
        
        guard let range = rangeOfString(string, options:[.AnchoredSearch, .CaseInsensitiveSearch]) else {
            return false
        }
        
        return range.startIndex == startIndex
    }
    
    func replace(target: String, withString: String) -> String
    {
        return self.stringByReplacingOccurrencesOfString(target, withString: withString, options: NSStringCompareOptions.LiteralSearch, range: nil)
    }
    
    
}