javascript - 无论对象数组中的深度如何，获取键值

Question

我有一个对象数组，我想在其中获取键的值，例如'多变的'。但 key 的深度是不同的，如下所示 -

[{
    "test": {
        "nameObj": {
            "name": "DateExpires",
            "title": "DateExpires",
            "variable": "DateTime"
        },
    }
}, 
{
    "test": {
        "nameObjSomethingElse": {
            "name": "DateExpires",
            "title": "DateExpires",
            "variable": "DateTime"
        },
    }
}, 
{
    "test": {
        "nameObjSomethingElse": {
            "name": "DateExpires",
            "title": "DateExpires",
           "anotherLevel": {
            "variable": "DateTime"
           }
        }
    }
}]

在数组中的每个对象中，键“变量”处于不同级别并在不同键下。如何获取“变量”的值？

Answer 1

您可以使用 JSON.stringify 并使用其回调函数来识别特定键的每个值:

const obj = [{
    "test": {
        "nameObj": {
            "name": "DateExpires",
            "title": "DateExpires",
            "variable": "DateTime"
        },
    }
}, 
{
    "test": {
        "nameObjSomethingElse": {
            "name": "DateExpires",
            "title": "DateExpires",
            "variable": "DateTime"
        },
    }
}, 
{
    "test": {
        "nameObjSomethingElse": {
            "name": "DateExpires",
            "title": "DateExpires",
           "anotherLevel": {
            "variable": "DateTime"
           }
        }
    }
}];
const variables = [];
JSON.stringify(obj, (key, val) => {
  if (key === 'variable') {
    variables.push(val);
  }
  return val;
});
console.log(variables);

或者，如果您想更多地手动递归:

const obj = [{
    "test": {
        "nameObj": {
            "name": "DateExpires",
            "title": "DateExpires",
            "variable": "DateTime"
        },
    }
}, 
{
    "test": {
        "nameObjSomethingElse": {
            "name": "DateExpires",
            "title": "DateExpires",
            "variable": "DateTime"
        },
    }
}, 
{
    "test": {
        "nameObjSomethingElse": {
            "name": "DateExpires",
            "title": "DateExpires",
           "anotherLevel": {
            "variable": "DateTime"
           }
        }
    }
}];
const recurse = (obj, arr=[]) => {
  Object.entries(obj).forEach(([key, val]) => {
    if (key === 'variable') {
      arr.push(val);
    }
    if (typeof val === 'object') {
      recurse(val, arr);
    }
  });
  return arr;
};
console.log(
  recurse(obj)
);