var flipbits = str => str.split('').map(b => (1 - b).toString()).join('');

​

    console.log(flipbits('010')); // outputs 101

    console.log(flipbits('101')); // outputs 010

 Run code snippet

var flipbits = function (v, digits) {

        return ~v & (Math.pow(2, digits) - 1);

    }

    console.log(flipbits(5, 3)); // outputs 2

    console.log(flipbits(2, 3)); // outputs 5

 Run code snippetHide results

var flipbits = function flipbits(str) {

      return str.split('').map(function (b) {

        return (1 - b).toString();

      }).join('');

    };

​

    console.log(flipbits('010')); // outputs 101

    console.log(flipbits('101')); // outputs 010

 Run code snippet