This is the JS code:

 const textLength = textContent.length;
    let string = '';
        for (let i = 0; i < textLength; i++) {
          if (string !== '' && offsetsSet.has(i)) {
            parts.push(string);
            string = '';
          }
          string += textContent[i];
        }

This is my swift code which I have ported to swift:

     override func getTextPart() -> String {
        guard let textNode = getLatest() as? TextNode else {
          return text
        }
        return textNode.text
      }
 public func splitText(splitOffsets: [Int]) throws -> [Node] {
      let textContent = getTextPart()
      let textLength = textContent.count
      let offsetsSet = Set(splitOffsets)
      var parts = [String]()
      var string = ""
    
          for i in 0..<textLength {
            if string != "" && offsetsSet.contains(i) {
              parts.append(string)
              string = ""
            }
              string += textContent[i] //Error: No exact matches in call to subscript 
          }
}

I'm getting error in this line: string += textContent[i]//Error: No exact matches in call to subscript. How do I write this in swift?