基于Typescript中嵌套对象数组的值进行过滤答案

【问题标题】：Filter based on value of nested array of objects in Typescript基于Typescript中嵌套对象数组的值进行过滤
【发布时间】：2019-08-27 19:57:09
【问题描述】：

我的 json 数据结构如下：

[
{"domain":"d1",
"technology":"Java",
"artifacts[{ 
  "artifactName":"app1",
  "hasVersionDiff":true,
  "environment":["DEV","SQA"],
  "version":["Not Available","1.0-R1"]
}]},

{"domain":"d2",
"technology":".net",
"artifacts[{ 
  "artifactName":"app4",
  "hasVersionDiff":false,
  "environment":["DEV","SQA"],
  "version":["1.0-R1","1.0-R1"]}]
}]

这个结果是 compareResults 变量。现在我试图根据每条记录的工件数据（hasVersionDiff 标志为真）来过滤它。我正在尝试使用以下过滤：

this.compareResults.map(function(ComparisonResult) {
        ComparisonResult.artifacts = ComparisonResult.artifacts.filter(x => x.hasVersionDiff == true)
    });

但它没有过滤，有人可以解释为什么这不起作用吗？

【问题讨论】：

你能分享你输入的预期输出吗？

标签： javascript arrays typescript object filter

【解决方案1】：

因为map，你需要return这个新项目。（我还修复了您的对象结构以使其有效）：

const compareResults = [{
    "domain": "d1",
    "technology": "Java",
    "artifacts": [{
      "artifactName": "app1",
      "hasVersionDiff": true,
      "environment": ["DEV", "SQA"],
      "version": ["Not Available", "1.0-R1"]
    }]
  },

  {
    "domain": "d2",
    "technology": ".net",
    "artifacts": [{
      "artifactName": "app4",
      "hasVersionDiff": false,
      "environment": ["DEV", "SQA"],
      "version": ["1.0-R1", "1.0-R1"]
    }]
  }
];

const modified = compareResults.map(function(ComparisonResult) {
  ComparisonResult.artifacts = ComparisonResult.artifacts.filter(x => x.hasVersionDiff);
  return ComparisonResult;
});

console.log(modified);

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

如果您想在artifacts 为空的情况下删除整个对象：

const compareResults = [{
    "domain": "d1",
    "technology": "Java",
    "artifacts": [{
      "artifactName": "app1",
      "hasVersionDiff": true,
      "environment": ["DEV", "SQA"],
      "version": ["Not Available", "1.0-R1"]
    }]
  },

  {
    "domain": "d2",
    "technology": ".net",
    "artifacts": [{
      "artifactName": "app4",
      "hasVersionDiff": false,
      "environment": ["DEV", "SQA"],
      "version": ["1.0-R1", "1.0-R1"]
    }]
  }
];

const modified = compareResults.map(function(ComparisonResult) {
  ComparisonResult.artifacts = ComparisonResult.artifacts.filter(x => x.hasVersionDiff);
  return ComparisonResult;
}).filter(({ artifacts }) => artifacts.length);

console.log(modified);

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

【讨论】：

谢谢杰克！效果很好，如果工件内部没有数据，有没有办法不返回域、技术？
@user2262292 怎么样？
耶耶耶耶耶耶耶耶！谢谢@Jack
总是乐于帮助@user2262292
一个问题，当我这样做时，我的原始数据似乎也在发生变化，对于 compareResults 的第二条记录，工件没有显示任何价值，有没有办法不修改原始数据？

【解决方案2】：

我实现了递归函数，使用该函数可以从上到下逐层过滤嵌套的对象数组。在TS playground中探索、播放和修改我的脚本

【讨论】：