Check if val in array and return new array with or without element.

new_gist_file

function pushIfUnique(array, val){
  var status = true;
	for (var i = 0; i < array.length; i++) {
		if (array[i]===val) { 
			status = false;
		}
	}
	if (status){
		array.push(val);
		return array;
	} else {
		return array;
	}
}