Question

我有一堆JSON，其中包含多个对象，数组，字符串，布尔值，数字等，这些对象存储在根级别和组件的一个对象中。

以下是示例：

{
  "theme": {
    "auto": {
      "sensor": "sensor.sn1_ldr",
      "below": 600
    },
    "ui": {
      "cards": {
        "round": false,
        "elevation": 1
      }
    },
    ...
  },
  ...
}

我设法像这样在数组中传递了项目的路径和新值：

["theme", "auto", "sensor"]

如何从那里设置该路径的新值？即。等同于：

config.theme.auto.sensor = newValue;

但是使用传递回的路径数组吗？

我到目前为止的方法：

handleConfigChange = (path, value) => {
  console.log(path, value);
  let config = this.state.config;
  // Set the new value

  this.setState({ config });
};

Answer 1

您可以存储最后一个键并通过从路径中获取键来缩小对象。

function setValue(object, path, value) {
    var last = path.pop();
    path.reduce((o, k) => o[k] = o[k] || {}, object)[last] = value;
}

var config = { theme: { auto: { sensor: "sensor.sn1_ldr", below: 600 }, ui: { cards: { round: false, elevation: 1 } } } },
    path = ["theme", "auto", "sensor"];

setValue(config, path, 'foo');

console.log(config);

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

Answer 2

下面是Nina答案的简单版本（使用reduce的答案）。

希望这可以帮助您了解背后的情况。

const setValueByPathArray = (object, path, value) => {
  let i = 0
  let reference = object
  while (i < path.length - 1) {
    const currentPath = path[i]
    reference = reference[currentPath]
    i += 1
  }
  const lastPath = path[path.length - 1]
  reference[lastPath] = value
  return object
}

const config = { theme: { auto: { sensor: "sensor.sn1_ldr", below: 600 }, ui: { cards: { round: false, elevation: 1 } } } }
const path = ["theme", "auto", "sensor"];

setValueByPathArray(config, path, 'foo')

Answer 3

使用Object.key获取键Array：

[https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/keys][1]

使用递归进行遍历。

const object1 = {
  "theme": {
    "auto": {
      "sensor": "sensor.sn1_ldr",
      "below": 600
    },
    "ui": {
      "cards": {
        "round": false,
        "elevation": 1
      }
    },

  },  
}

var result = [];
see(object1);
console.log(result);

function see (obj){
    var k = Object.keys(obj)
    for (var i = 0; i < k.length; i++){
        result.push(k[i]);
        if (obj[k[i]] instanceof Object){
            see(obj[k[i]]);
        }
    }
}

[1]：https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/keys

从键数组中设置对象/数组中的嵌套项

3 个答案: