30-binary-numbers.js

var n = parseInt(readLine());
const countArray=[];
let count=0;
let inputBinary = n.toString(2).split('');
inputBinary.forEach((digit, index)=>{
  if(digit==='1'){
    count++;
    if(index===inputBinary.length-1){
      countArray.push(count);
    }
  }else{
    countArray.push(count);
    count=0;
  }
});
console.log(countArray.sort((a,b)=>b-a)[0]);