Capitalize first letters

 function capitalizeFirst (array) {
  // add whatever parameters you deem necessary - good luck!
//   var capitalizeFirst = function(array) {
    if (array.length === 0) return [];
  
  let chars = array[0].split('');
  chars[0] = chars[0].toUpperCase();
  
  return [chars.join('')].concat(capitalizeFirst(array.slice(1)));
  
}
// }

capitalizeFirst(['car','taco','banana']); // ['Car','Taco','Banana']