answer.js

//map implementation
function newmap(arr, func) {
  var newarr = [];
  for(var i = 0; i < arr.length; ++i) {
    newarr.push(func(arr[i]));
  }
  return newarr;
}

function newfilter(arr, func) {
  var newarr = [];
  for(var i = 0; i < arr.length; ++i) {
    if(func(arr[i])) newarr.push(arr[i]);
  }
  return newarr;
}

console.log(newmap(array, (x) => {
  if(typeof x == typeof "")
    return x + "$";
  else return undefined;
}));

console.log(newfilter(filterarray, (x) => {
  return x;
}));

var strarray = ["asdfzxcv", "asdf", "zxc", "qwersdfg"];

console.log(newfilter(strarray, (x) => {
  return x.length > 3;
}));

//!! converting a value to boolean and inverting it twice

//javascript was originally called livescript but before shipping the name was changed to Javascript, which was said to be a
//ploy to make javascript more popular