javascript - 将字符串值转换为 JavaScript 中的变量引用

Question

我有以下代码，我尝试使用另一个 JSON 对象的变量引用一个 JSON 对象的值:

const ch = {
  "columns": {
    "COL1": {
      "position": 1,
      "composites": ["VAR1", "VAR3"]
    },
    "COL2": {
      "position": 3,
      "composites": ["VAR2"]
    },
    "COL3": {
      "position": 2,
      "composites": ["VAR4"]
    }
  }
}

const dataset = [{
    "VAR1": "alpha",
    "VAR2": 2,
    "VAR3": "1015",
    "VAR4": "z",
  },
  {
    "VAR1": "beta",
    "VAR2": 701,
    "VAR3": "1023",
    "VAR4": "z"
  }
]

for (let l = 0; l < dataset.length; l++) {
  for (const {
      position,
      composites
    } of Object.values(ch.columns).sort((a, b) => a.position - b.position)) {
    console.log(position, composites[0], dataset[l].VAR1)
    /* eval[dataset[l].composites[0]], this[dataset[l].composites[0]]*/
  }
}

程序正确地对列进行排序，我可以引用“ch”中的两个值，但我想使用第一个复合值作为对数据集的变量引用。在谷歌上搜索了这个问题后，我遵循了一些使用“this”或“eval”的建议，但都不起作用。我哪里出错了？

理想情况下，如果我能让注释掉的代码正常工作，日志应该如下所示:

1 VAR1 alpha alpha 
2 VAR4 alpha z
3 VAR2 alpha 2
1 VAR1 beta  beta
2 VAR4 beta  z
3 VAR2 beta  701

Answer 1

使用dataset[l][composites[0]]获取附加列。请参阅Dynamically access object property using variable

const ch = {
  "columns": {
    "COL1": {
      "position": 1,
      "composites": ["VAR1", "VAR3"]
    },
    "COL2": {
      "position": 3,
      "composites": ["VAR2"]
    },
    "COL3": {
      "position": 2,
      "composites": ["VAR4"]
    }
  }
}

const dataset = [{
    "VAR1": "alpha",
    "VAR2": 2,
    "VAR3": "1015",
    "VAR4": "z",
  },
  {
    "VAR1": "beta",
    "VAR2": 701,
    "VAR3": "1023",
    "VAR4": "z"
  }
]

for (let l = 0; l < dataset.length; l++) {
  for (const {
      position,
      composites
    } of Object.values(ch.columns).sort((a, b) => a.position - b.position)) {
    console.log(position, composites[0], dataset[l].VAR1, dataset[l][composites[0]])
  }
}