问函数没有看到Object属性，但是console.log看到了

EN

let myLibrary = []; //to store my Book Objects

function Book(title, author, onPage, totalPages) { //constructor function
  this.title = title;
  this.author = author;
  this.onPage = onPage;
  this.totalPages = totalPages;
  this.info = function() {
    return this;
  }
}

function addBookToLibrary() {
  let a = document.getElementById('bookTitle').value;
  let b = document.getElementById('authorName').value;
  let c = document.getElementById('onPage').value;
  let d = document.getElementById('numOfPages').value;
  myLibrary.push(new Book(a, b, c, d));
}

function showBooks() {
  for (i = 0; i <= myLibrary.length; i++) {
    if (Number(myLibrary[i].onPage) < Number(myLibrary[i].totalPages)
      let newLi = document.createElement('li');
      newLi.innterText = myLibrary[i].title + ' by ' + myLibrary[i].author;
      inProgressBooks.prepend(newLi);
    }
  }
}