编辑代码

function convent(n) {
  	let neg = false;
	let remainder = 0;
	let result = "";
  
	if(n<0){
    	n *= -1;
      	neg = true;
    }
  
	do{
      remainder = n % 7;
      n = Math.floor(n / 7);
      result += remainder.toString();
    }while(n);
  
	result = result.split('').reverse().join('');

  	return neg ? "" + result : result;
}

console.log(convent(7));
console.log(convent(2019));