方法一：

function bouncer(arr) {
// Don't show a false ID to this bouncer.
arr=arr.filter(function(val){if(val){return val;}});
  return arr;
}
bouncer([7, "ate", "", false, 9]);

方法二：

function bouncer(arr) {
  // Don't show a false ID to this bouncer.
  return arr.filter(function(value){
    return (value!==false && value!==null && value!==undefined && value!==0 && value!=='') && !(typeof value === 'number' && value.toString() === 'NaN');
  });
}


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