The function called fakeBinary receives as argument size(size) which is a number (integer) and must return a string of 1s and 0s with the indicated size.

fakeBinary.js

let result = []

const REGEX_INT = /^-?\d+$/;

const isNumber = (value) => {
  return REGEX_INT.test(value);
}

const fakeBinary = (param) => {
  if (isNumber(param)){
    for (let i = 0; i < param; i++) {
      if(i % 2 === 0) {
        result.push(1);
      } else {
        result.push(0);
      }
    } 
    console.log(result.map((bin, index) => (bin)).join(''));
  } else {
    console.log('Is not a Number, please enter a valid Number');
  }
}