使用 JavaScript 将字符串转换为对象

Question

我想知道在 JavaScript 中将此字符串转换为对象的最有效方法。

这是丑陋的字符串：

  "\"date\",\"initRegistrations\",\"registrations\",\"finalizeRegistrations\"\r\n\"03/29/2017\",\"0\",\"0\",\"0\"\r\n\"03/30/2017\",\"5\",\"4\",\"4\"\r\n\"03/31/2017\",\"42\",\"0\",\"0\"\r\n\"04/01/2017\",\"192\",\"0\",\"0\"\r\n\"04/02/2017\",\"4\",\"0\",\"0\"\r\n\"04/03/2017\",\"23\",\"0\",\"0\"\r\n\"04/04/2017\",\"5\",\"0\",\"0\"\r\n"

目前我正在使用这个函数，但它不能正常工作，预期的输出将是一个带有键日期、initRegistrations、registrations、finalizeRegistrations 的对象对象：

   function convertToArrayOfObjects(data) {
    var keys = data.shift(),
        i = 0, k = 0,
        obj = null,
        output = [];

    for (i = 0; i < data.length; i++) {
        obj = {};

        for (k = 0; k < keys.length; k++) {
          if(data[i][k]){
            obj[keys[k]] = data[i][k];
          }

        }

        output.push(obj);
    }

    return output;
}

有没有什么花哨的方法可以轻松实现这一点，或者我应该去玩我的对象数组？ 任何帮助或建议表示赞赏。 谢谢。

Answer 1

可能对某些人来说太实用了，但我就是这样写的。

const s =   "\"date\",\"initRegistrations\",\"registrations\",\"finalizeRegistrations\"\r\n\"03/29/2017\",\"0\",\"0\",\"0\"\r\n\"03/30/2017\",\"5\",\"4\",\"4\"\r\n\"03/31/2017\",\"42\",\"0\",\"0\"\r\n\"04/01/2017\",\"192\",\"0\",\"0\"\r\n\"04/02/2017\",\"4\",\"0\",\"0\"\r\n\"04/03/2017\",\"23\",\"0\",\"0\"\r\n\"04/04/2017\",\"5\",\"0\",\"0\"\r\n";

// Remove surrounding quotes from a string.
const removeQuotes = s => s.replace(/^"|"$/g, '');

// Split input by newline ('\r\n')
const lines = s.trim().split('\r\n');

// Get header (first line of input) and remove quotes.
const header = lines[0].split(',').map(removeQuotes)

// The rest of the string is data. Split by comma and remove quotes.
const data = lines.splice(1).map(line => line.split(',').map(removeQuotes));

// Given header row and data row, combine into an object.
const zipWith = header => row => {
  return header.reduce((map, item, index) => {
    map[item] = row[index];
    return map;
  }, {});
}

// Now process all your data with a map :)
const result = data.map(zipWith(header));

console.log(result);

非常确定输出正是您想要的：

[
  {
    "date": "03/29/2017",
    "initRegistrations": "0",
    "registrations": "0",
    "finalizeRegistrations": "0"
  },
  {
    "date": "03/30/2017",
    "initRegistrations": "5",
    "registrations": "4",
    "finalizeRegistrations": "4"
  },
  {
    "date": "03/31/2017",
    "initRegistrations": "42",
    "registrations": "0",
    "finalizeRegistrations": "0"
  },
  {
    "date": "04/01/2017",
    "initRegistrations": "192",
    "registrations": "0",
    "finalizeRegistrations": "0"
  },
  {
    "date": "04/02/2017",
    "initRegistrations": "4",
    "registrations": "0",
    "finalizeRegistrations": "0"
  },
  {
    "date": "04/03/2017",
    "initRegistrations": "23",
    "registrations": "0",
    "finalizeRegistrations": "0"
  },
  {
    "date": "04/04/2017",
    "initRegistrations": "5",
    "registrations": "0",
    "finalizeRegistrations": "0"
  }
]

Answer 2

您可能正在寻找 split，它可以从字符串中创建一个数组：

var a = s.split("\r\n");

这将为您提供一个字符串包含的行数组。然后，如果您需要每行中的字段，您可以在 for 循环中使用另一个分隔符（逗号？）进一步 split。

var tbl=[];
var rows = s.split("\r\n");
for(var y in rows) {
    var row = rows[y].split('"');
    tbl.push(row);
} 

这将为您提供一个数组数组。只需最少的努力，您就可以改进它以识别带有字段名称的标题行，然后将它们用作每行的键。 （注意：我现在在移动设备上，所以这是我能为您做的最好的事情，但如果您仍然迷路，我可以稍后再向您展示更详细的示例。）