有人能确定我为什么把索引弄得超出范围吗?

我试图从一个文件中读取数据并将其存储在二维数组中。

我正面临一个错误“temparr[x]=number!”索引超出范围。

我找不到问题的原因。

    func loadData(){

        let path = "/Users/ushehri/Desktop/imageData/imageData/imageData/imageData.txt"

        let filemgr = FileManager.default
        if filemgr.fileExists(atPath: path){

            do {
                var x = 0

                let fullData = try String(contentsOfFile: path, encoding: String.Encoding.utf8)

                let readings = fullData.components(separatedBy: ",") as [String]
                var tempArr = [Double]()
                for i in 0..<readings.count {

                    let number = Double(readings[i])

                        tempArr[x] = number!
                        x = x + 1
                        if( x == 8){
                            x = 0
                        imageNumber.append(tempArr)
                        tempArr.removeAll()
                    }


                }

                for z in 0...readings.count{
                    for r in 0...8 {
                        print(imageNumber[z][r])
                    }
                }



            } catch let error as NSError{
                print("Error: \(error)")
            }

        }
    }