JS is so meh to write in, why learn it here. Instead, learn DRUL, the assembler made for solving Rudy The Red Dot:

code = compile(".:dddddrruuuul@.");

var colors = [];

var acc = 0;

function run(instructions) { var pc = 0;

   while (pc < instructions.length) {
     var line = instructions[pc];
   var op = line[0];
     var args = line[1];
     switch (op) {
       case "a": // set accumulator (set to remainingDots() if no arg)
  a(args[0]);
  break;
       case "+": // add to accumulator (+1 if no arg)
  add(args[0]);
  break;
       case "-": // subtract from accumulator (-1 if no arg)
  sub(args[0]);
  break;
       case "u": // up n squares (1 if no arg)
  u(args[0]);
  break;
       case "d": // down n squares (1 if no arg)
  d(args[0]);
  break;
       case "l": // left n squares (1 if no arg)
  l(args[0]);
  break;
       case "r": // right n squares (1 if no arg)
  r(args[0]);
  break;
       case "g": // get current square color: color index n, unshift if -1, or push if no arg
  g(args[0]);
  break;
       case "s": // set current square color: color index n, pop if -1, or shift if no arg
  s(args[0]);
  break;
       case "=": // if current square color is literal (b / r / g / y / w) or color index n then jump to label
  if (eq(args[0])) {
   pc = args[1];
   continue;
  }
  break;
       case "!": // if current square color is not literal (b / r / g / y / w) or color index n then jump to label
  if (!eq(args[0])) {
   pc = args[1];
   continue;
  }
  break;
       case "@": // jump to label
  pc = args[0];
  continue;
       case "0": // if accumulator is 0 then jump to label
  if (acc == 0) {
    pc = args[0]
    continue;
  }
  break;
       case "~": // if accumulator is not 0 then jump to label
  if (acc != 0) {
    pc = args[0]
    continue;
  }
  break;
        }
  pc++;
   }
 }


 run(code);


 function compile(code) {
  var instructions = [];
   var waiting_for_op = true;
   var max_args = 0;
   var skip_if_non_number = false;
   var op = "";
   var label = "";
   code += "     ";

   var i = 0;
   var line = [];
   var args = [];

   while (i < code.length) {
     var c = code[i];
     if (!waiting_for_op && skip_if_non_number && c != "-" && isNaN(parseInt(c))) {
  line.push(args);
  instructions.push(line);
  line = [];
  waiting_for_op = true;        
     }     
     if (waiting_for_op) {
       if (c == " ") {
  i++
  continue;
       }
       if (code[i+1] == ":") {
  label = c;
  i += 2;        
  op = code[i];
       }
       else {
  label = "";
     op = c;
       }
       waiting_for_op = false;
       line = [label, op];
       args = [];
       skip_if_non_number = (op == "u" || op == "d" || op == "l" || op == "r");
       if (op == "=" || op == "!")
  max_args = 2;
       else
  max_args = 1;      
     }
     else {
       if (c == " ") {
  line.push(args);
  instructions.push(line);
  line = [];
  waiting_for_op = true;        
       }        
    else {
  var negate = false;
  if (c == "-") {
    negate = true;
    i += 1;
    c = code[i];
  }
  var num = parseInt(c);
  if (isNaN(num)) {
    if (c == "b")
      args.push("blue");
    else if (c == "r")
      args.push("red");
    else if (c == "y")
      args.push("yellow");
    else if (c == "g")
      args.push("green");
    else if (c == "w")
      args.push("white");
    else
      args.push(c);          
  } 
  else {          
    c = "";
    while (!isNaN(num)) {
      c += code[i];
      i++;
      num = parseInt(code[i]);
    }
    num = parseInt(c);
    if (negate) num = -num;      
    i--;
    args.push(num);
  }
  if (max_args > 0 && args.length >= max_args) {
    line.push(args);
    instructions.push(line);
    line = [];
    waiting_for_op = true;       
  }
       }
     }

     i++;
   }

   for (i = 0; i < instructions.length; i++) {
     line = instructions[i];
     op = line[1];
     if (op == "=" || op == "!")
       instructions[i][2][1] = get_label(instructions, instructions[i][2][1]);
     else if (op == "@" || op == "0" || op == "~")
       instructions[i][2][0] = get_label(instructions, instructions[i][2][0]);

   }

   for (i = 0; i < instructions.length; i++) 
  instructions[i].shift();

   return instructions;
 }



 function get_label(lines, label) {
   for (var i = 0; i < lines.length; i++) {
     if (lines[i][0] == label)
       return i;
   }
   return -1;
 }


 function repeat(fn, n) {
   if (n == undefined)
     fn();
   else
  for (var i = 0; i < n; i++)
  fn();
 }

 function eq(color) {
   if (typeof(color) == "number")
     color = colors[color];
   if (color == "white")
     color = false;
   return color == getColor();
 }

 function g(c) {
  color = getColor();
   if (!color) 
     color = "white";

   if (c == undefined)
     colors.push(getColor());
   else if (c == -1)
     colors.unshift(getColor());
   else
  colors[c] = getColor();
 }

 function s(c) {
   if (c == undefined)
     color = colors.shift();
   else if (c == -1)
     color = colors.pop();
   else
     color = colors[c];

   if (color == "white")
     color = false;
   setColor(color);
 }

 function u(n) {
   repeat(up, n);
 }

 function d(n) {
   repeat(down, n);
 }

 function r(n) {
   repeat(right, n);
 }

 function l(n) {
   repeat(left, n);
 }

 function a(n) {
   if (n == undefined)
     acc = remainingDots();
   else
     acc = n;
 }

 function add(n) {
   if (n == undefined)
     acc++;
   else
  acc += n;
 }

 function sub(n) {
   if (n == undefined)
     acc--;
   else
     acc -= n;
 }

 // level  1  d7r5u2r2
 // level  2  d6r3u2r2d3
 // level  3  d2 g d3r2 s r2u
 // level  4  d4r1g ds r2urg ds r2
 // level  5  .:r2 =bB =rR r B:d @. R:u @.
 // level  6  r =bB u4 =b> lu >:ru B:d4 =b< rd <:ld
 // level  7  .:=r> d @. >:r2 u9 @.
 // level  8  d8 r2 u7 r2 d7 r2 u7 r2 d7 r1
 // level  9  .:r100 d100 @.
 // level 10  a8 .:d g - ~. dr a8 #:s ru - ~# u
 // level 11  .:=gG=yY=bB=rR G:r=wG@. Y:d=wY@. B:u=wB@. R:l=wR@.