javascript十进制转化为二进制

function toBin(intNum) {
var answer = "";
if(/\d+/.test(intNum)) {
  while(intNum != 0) {
   answer = Math.abs(intNum%2)+answer;
   intNum = parseInt(intNum/2);
  }
  if(answer.length == 0)
   answer = "0";
   return answer;
} else {
    return 0;
}
}