Question

我有一个像这样的对象数组。

var books = [{
id : 1,
name : 'Name of the wind',
year : 2015,
rating : 4.5,
author : 2}];

现在我有一个函数editBooks，它询问用户的id并用相同的id替换用户给出的值的书。例如

function editBooks(name,author,year,rating,id)

如何根据用户提供的id替换books数组中对象的内容？

Answer 1

您可以搜索id并使用该书进行更新。如果未找到任何书籍，请生成新条目。

＆＃13;

function editBooks(name, author, year, rating, id) {
    var book = books.find(b => b.id === id);
    if (book) {
        book.name = name;
        book.author = author,
        book.year = year;
        book.rating = rating;
    } else {
        books.push({ id, name, author, year, rating });
    }
}

var books = [{ id: 1, name: 'Name of the wind', year: 2015, rating: 4.5, author: 2 }];

editBooks('Foo', 2017, 3.3, 5, 1);
editBooks('bar', 2016, 1, 2, 2);
console.log(books);

＆＃13;

为了稍微好一点的实现，我会将id移到参数的第一位，并使用对所有参数的检查来仅更新非undefined的参数，因为可能的更新只有一处房产。

Answer 2

您可以将object作为参数传递给您的函数，并使用for...in循环来更新具有相同ID的对象（如果找到）。

＆＃13;

var books = [{id: 1,name: 'Name of the wind',year: 2015,rating: 4.5,author: 2}];

function editBooks(obj) {
  books.forEach(function(e) {
    if(obj.id && obj.id == e.id) {
      for(var i in obj) e[i] = obj[i]
    }
  })
}

editBooks({id:1, name: 'New name', author: 22})
console.log(books)

＆＃13;

Answer 3

尝试以下代码段，

function editBooks(name,author,year,rating,id) {
    var found = false;
    books.forEach(function(book) {
        if(book.id == id) {
           book.name = name;
           book.year = year ;
           book.author = author;
           book.rating = rating;
           found = true;
        }
   });
   return found; // if found is false, then you can insert new book
}

Answer 4

最好传递一个只包含更改的对象（一个只包含一个或多个属性的对象来更改它们的值）

一般情况下，您可以按照以下步骤进行操作;

＆＃13;

var books = [{id : 1, name : 'Name of the wind', year : 2015, rating : 4.5, author : 2}, {id : 2, name : 'River Guard', year : 2016, rating : 6.5, author : "John Doe"}];
Object.assign(books.find(b => b.id === 2),{author: "Jane Doe"});
console.log(books);

＆＃13;

转入类似

的功能

function editBook(bookList, id, edits){
  Object.assign(bookList.find(b => b.id === id),edits);
  return bookList;
}

是微不足道的。

Answer 5

仅更新更改的值。
如果他们的ID不存在，并且如果新书有，则会添加新书未定义的值将这些值设置为undefined。

＆＃13;

var books = [
  {
id : 1,
name : 'Name of the wind',
year : 2015,
rating : 4.5,
author : 2},
{id:2,
name : 'Name of the 2',
year : 2015,
rating : 4.5,
author : 2},
{id:3,
name : 'Name of the 3',
year : 2015,
rating : 4.5,
author : 2}
];

function editBooks(books,id,name,year,rating,author){
const update = book => Object.assign(book, { id:book.id,name: name || book.name,year: year || book.year,rating: rating || book.rating,author: author || book.author});
let details = books.find((book)=>{ return book.id===id });
details ? update(details):books.push({id,name ,year,rating, author});
};

//edit if exists
editBooks(books,2,'Updated Title','1985');
// add if id does not exist
editBooks(books,4,'A Whole New Title', 2015 );
console.log(books)

＆＃13;

.as-console-wrapper { max-height: 100% !important; top: 0; }

＆＃13;

在javascript中的对象数组中基于id替换特定对象

5 个答案: