var library = [   
   { author: 'Bill Gates', title: 'The Road Ahead', libraryID: 1254},  
   { author: 'Steve Jobs', title: 'Walter Isaacson', libraryID: 4264},  
   { author: 'Suzanne Collins', title: 'Mockingjay: The Final Book of The Hunger Games', libraryID: 3245}  
   ];  
  
function compare_to_sort(x,y)   
 {  
  if (x.title < y.title)  
    return -1;  
  if (x.title > y.title)  
    return 1;  
  return 0;  
 }  
  
console.log(library.sort(compare_to_sort));