function mcuString(str){
  if(str){
    var count = 0;
    var len  = str.length;
    for(var i = 0; i <len; i++){
      if(str.charCodeAt(i) > 0 && str.charCodeAt(i) <= 255){
        count ++;
      }else{
        count += 2;;
      }
    }
    return count;
  }
}

var test = mcuString("hello World!");
console.log(test)