键/值对的 JavaScript 数组使用文字变量名作为键
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原文地址: http://stackoverflow.com/questions/18491828/
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JavaScript Array of Key/Value Pairs Uses Literal Variable Name for Key
提问by Raj
I'm trying to create an array of key/value pairs by using the pushmethod, but getting unexpected results.
我正在尝试使用该push方法创建一个键/值对数组，但得到了意想不到的结果。
console.logprints this:
console.log打印这个：
books: [{"bookTitle":"Mark Twain"}]
书籍：[{"bookTitle":"马克吐温"}]
Whereas I would expect this:
而我希望这样：
books: [{"Tom Sawyer" : "Mark Twain"}]
书籍：[{“汤姆索亚”：“马克吐温”}]
Here's the code:
这是代码：
var books = [];
var bookTitle = "Tom Sawyer";
var author = "Mark Twain";
books.push({bookTitle : author})
console.log("books: %s", JSON.stringify(books))
I've tried books.bookTitle = authorand books[bookTitle] = author, but the result is the same. Any help is appreciated.
我试过books.bookTitle = authorand books[bookTitle] = author，但结果是一样的。任何帮助表示赞赏。
回答by Matt Ball
Bracket notationis the correct way to use a dynamic key name:
括号表示法是使用动态键名的正确方法：
books[bookTitle] = author
However, you need to use an intermediate object:
但是，您需要使用中间对象：
var books = [];
var bookTitle = "Tom Sawyer";
var author = "Mark Twain";
var foo = {};
foo[bookTitle] = author;
books.push(foo);
console.log("books: %s", JSON.stringify(books))
回答by Lee Benson
In modern Javascript (ES2015+), you can use computed propertieswhich modifies your example code in one slight way-- square brackets are wrapped around the key name to signify it should be computed beforeassignment:
在现代 Javascript (ES2015+) 中，您可以使用计算属性以一种轻微的方式修改您的示例代码——方括号括在键名周围以表示它应该在赋值之前计算：
var books = [];
var bookTitle = "Tom Sawyer";
var author = "Mark Twain";
books.push({[bookTitle] : author})
... which correctly yields:
...正确产生：
[ { 'Tom Sawyer': 'Mark Twain' }
[{'汤姆索亚'：'马克吐温'}
This is similar to Matt Ball's original answer, but avoids the verbosity of using temporary variables.
这类似于 Matt Ball 的原始答案，但避免了使用临时变量的冗长。
