与对象数组进行比较和数组，并返回匹配对象的一部分答案

【问题标题】：Compare and Array to an array of objects and return a part of the matched objects与对象数组进行比较和数组，并返回匹配对象的一部分
【发布时间】：2020-09-26 03:58:37
【问题描述】：

下面有一个对象数组

const response = 
[
{
    id: 105,
    label: 'test',
    directories: [ '/api/1/directories/500' ]
  },
  {
    id: 337,
    label: 'test2',
    directories: [ '/api/1/directories/766' ]
  },
  {
    id: 200,
    label: 'test20',
    directories: [ '/api/1/directories/95' ]
  }
]

我有一个名为目录的数组

directories = [ '/api/1/directories/766', '/api/1/directories/95' ]

我正在尝试搜索/过滤响应以仅返回与目录数组中的目录匹配的对象的 ID

所以示例输出可能如下所示，它只是匹配对象的 ID

sampleOut= [337, 200]

【问题讨论】：

这能回答你的问题吗？ Javascript find json value

标签： javascript

【解决方案1】：

如果有匹配，您可以遍历主数组并推送您想要的属性：

const response = 
[
{
    id: 105,
    label: 'test',
    directories: [ '/api/1/directories/500' ]
  },
  {
    id: 337,
    label: 'test2',
    directories: [ '/api/1/directories/766' ]
  },
  {
    id: 200,
    label: 'test20',
    directories: [ '/api/1/directories/95' ]
  }
]

var directories = [ '/api/1/directories/766', '/api/1/directories/95' ]

var sampleOut = []

response.forEach(function(a) {
  if (directories.indexOf(a.directories[0]) >= 0 ) {
    sampleOut.push(a.id)
  }
})

console.log(sampleOut)

【讨论】：

【解决方案2】：

const sampleOut = response.filter(response => directories.includes(response.directories[0]))
    .map(response => response.id);

【讨论】：

【解决方案3】：

这可以按如下方式完成：

const out = response.filter(o => directories.includes(o.directories[0])).map(o => o.id);

请看下面的可运行代码sn-p。

const response = [
  {
    id: 105,
    label: 'test',
    directories: [ '/api/1/directories/500' ]
  },
  {
    id: 337,
    label: 'test2',
    directories: [ '/api/1/directories/766' ]
  },
  {
    id: 200,
    label: 'test20',
    directories: [ '/api/1/directories/95' ]
  }
];

const directories = [ '/api/1/directories/766', '/api/1/directories/95' ];

const out = response.filter(o => directories.includes(o.directories[0])).map(o => o.id);
console.log(out)

【讨论】：

【解决方案4】：

您可以使用reduce 并通过indexOf 检查是否存在

const response = 
[
{
    id: 105,
    label: 'test',
    directories: [ '/api/1/directories/500' ]
  },
  {
    id: 337,
    label: 'test2',
    directories: [ '/api/1/directories/766' ]
  },
  {
    id: 200,
    label: 'test20',
    directories: [ '/api/1/directories/95' ]
  }
]

directories = [ '/api/1/directories/766', '/api/1/directories/95' ];

var result = response.reduce((acc, item)=>{

  if(directories.indexOf(item.directories[0]) > -1){
    acc.push(item.id);
    
  }
  return acc;
},[]);

console.log(result);

【讨论】：

我收到 UnhandledPromiseRejectionWarning: TypeError: Cannot read property '0' of undefined at Array.reduce ()
没关系，数组在我填写后首先被声明为空，我得到了正确的数据

【解决方案5】：

你可以这样做。

const response = 
[
{
    id: 105,
    label: 'test',
    directories: [ '/api/1/directories/500' ]
  },
  {
    id: 337,
    label: 'test2',
    directories: [ '/api/1/directories/766' ]
  },
  {
    id: 200,
    label: 'test20',
    directories: [ '/api/1/directories/95' ]
  }
];

const directories = [ '/api/1/directories/766', '/api/1/directories/95' ];

const res = response.reduce((acc, elem)=>{
  if(directories.includes(elem.directories[0])){
    acc.push(elem.id)
  }
  return acc
},[]);

console.log(res)

【讨论】：