Question

我想知道如何遍历Javascipt中嵌套的对象数组吗？我有一个名为obj的示例对象。我想根据条件'in'是'string'和'out''number'来检索对象。

// tried got stuck
const output = [];
    myList.forEach(entry => {
      Object.keys(entry).forEach(key => {
        const entity = entry[key][0];
        if (entity.in === "string" && entity.out === "number") {
          output.push(entity);
        }
      });
    });

var obj = [{
    "ston": [{
      "id": "identity1",
      "in": "string",
      "out": "number",
      "value": 10
    },{
        "id": "identity2",
        "in": "string",
        "out": "number",
        "value": 10
    }],
    "nton": [{
      "id": "identity1",
      "in": "number",
      "out": "number",
      "value": 20
    },{
      "id": "identity2",
      "in": "number",
      "out": "number",
      "value": 30
    }]
  }]

预期产量

   [{
      "id": "identity1",
      "in": "string",
      "out": "number",
      "value": 10
    },{
        "id": "identity2",
        "in": "string",
        "out": "number",
        "value": 10
    }]

Answer 1

简单的递归函数：

var obj = [{
  "ston": [{
    "id": "identity1",
    "in": "string",
    "out": "number",
    "value": 10
  }, {
    "id": "identity2",
    "in": "string",
    "out": "number",
    "value": 10
  }],
  "nton": [{
    "id": "identity1",
    "in": "number",
    "out": "number",
    "value": 20
  }, {
    "id": "identity2",
    "in": "number",
    "out": "number",
    "value": 30
  }]
}];

function getObjects(inVal, outVal) {
  var matches = [];
  obj.forEach(child => {
    Object.values(child).forEach(arr => {
      if (arr.some(e => e.in == inVal && e.out == outVal)) {
        matches.push([...arr.filter(e => e => e.in == inVal && e.out == outVal)]);
      }
    });
  });
  return matches.flat();
}

console.log(getObjects("string", "number"));

Answer 2

在这里，您有一个解决方案，主要使用Array.reduce()遍历数组的外部对象，从每个外部对象获取值的展平数组，以创建具有内部对象的数组，然后过滤满足条件的对象条件，同时将它们保存在新数组中：

var obj = [
  {
    "ston": [
      {"id": "identity1", "in": "string", "out": "number", "value": 10},
      {"id": "identity2", "in": "string", "out": "number", "value": 10}
    ],
    "nton": [
      {"id": "identity1", "in": "number", "out": "number", "value": 20},
      {"id": "identity2", "in": "number", "out": "number", "value": 30}
    ]
  }
];

let res = obj.reduce((acc, o) =>
{
    acc = acc.concat(Object.values(o).flat().filter(
        o => o.in === "string" && o.out === "number"
    ));
    return acc;
}, []);

console.log(res);

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

使用过的方法的其他文档：

或者，经过一段时间的思考，您可以将下一个简化版本与Array.map()

一起使用

var obj = [
  {
    "ston": [
      {"id": "identity1", "in": "string", "out": "number", "value": 10},
      {"id": "identity2", "in": "string", "out": "number", "value": 10}
    ],
    "nton": [
      {"id": "identity1", "in": "number", "out": "number", "value": 20},
      {"id": "identity2", "in": "number", "out": "number", "value": 30}
    ]
  }
];

let res = obj.map(Object.values).flat(2).filter(
    o => o.in === "string" && o.out === "number"
);

console.log(res);

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

Answer 3

您可以使用将该对象重建为嵌套数组，然后展平，最后select distinct /* I believe the sys.sys views were added in 2012 or so, still works in 2017 */ od.name caller_procedure_name ,o.name called_procedure_name from sys.sysdepends d inner join sys.sysobjects o on o.id = d.depid and o.type = 'P' inner join sys.sysobjects od on od.id = d.id and od.type = 'P' select distinct /* should work all the way back to sql 2000, still works in 2017 */ od.name caller_procedure_name ,o.name called_procedure_name from dbo.sysdepends d inner join dbo.sysobjects o on o.id = d.depid and o.type = 'P' inner join dbo.sysobjects od on od.id = d.id and od.type = 'P'。

filter

如何遍历JavaScript中的嵌套数组对象

3 个答案: