iOS swift 5: 直接移除字串中不是數字的字元

字串中不是數字的直接移除
 解決方案來源:
  Filter non-digits from string

 sStrTmp2 = sStrTmp1.components(separatedBy:CharacterSet.decimalDigits.inverted).joined(separator: "")
 if( sStrTmp2.count > 0)
 {
  if let nNumber = Int(sStrTmp2)
  {
  }
 } 

字串的字元檢查

  sStrTmp1 = "0123456789"
  for nChar in sStrTmp1  /* 檢查是否為數字字元 */
  {
   if( nChar < "0" || nChar > "9")
   {
    bIsNumber = false
   }
  }