http://www.freecodecamp.com/v3rse 's solution for Bonfire: Falsy Bouncer

bonfire-falsy-bouncer?solution=function%20bouncer(arr)%20%7B%0A%20%20%2F%2F%20Don%27t%20show%20a%20false%20ID%20to%20this%20bouncer.%0A%20%20return%20arr.filter(function(val)%7B%0A%20%20%20%20return%20%20Boolean(val)%3B%0A%20%20%7D)%3B%0A%7D%0A%0Abouncer(%5B7%2C%20%22ate%22%2C%20%22%22%2C%20false%2C%209%5D)%3B%0A.js

// Bonfire: Falsy Bouncer
// Author: @v3rse
// Challenge: http://www.freecodecamp.com/challenges/bonfire-falsy-bouncer?solution=function%20bouncer(arr)%20%7B%0A%20%20%2F%2F%20Don%27t%20show%20a%20false%20ID%20to%20this%20bouncer.%0A%20%20return%20arr.filter(function(val)%7B%0A%20%20%20%20return%20%20Boolean(val)%3B%0A%20%20%7D)%3B%0A%7D%0A%0Abouncer(%5B7%2C%20%22ate%22%2C%20%22%22%2C%20false%2C%209%5D)%3B%0A
// Learn to Code at Free Code Camp (www.freecodecamp.com)

function bouncer(arr) {
  // Don't show a false ID to this bouncer.
  return arr.filter(function(val){
    return  Boolean(val);
  });
}

bouncer([7, "ate", "", false, 9]);

Confusing sometimes which function return values, which ones alter then and which ones do both.