有没有类似于 PHP 的 array_column 的 Javascript 函数？

Question

我正在使用 Vue.js

我想要的是从多维数组中得到一列名为'name'。

我不确定这个多维数组的维度大小。

样本数组在这里

{
    "form":{
        "id":"123465",
        "title":"User Information",
        "fields":[
                    {
                        "type":"date",
                        "title":"Document date",
                        "name":"document_date",
                        "required":true
                    },
                    {
                        "type":"input",
                        "title":"Document no",
                        "name":"document_no",
                        "required":true
                    }
                ],
        "tabs":{
            "xxx-general":{
                "title":"General",
                "fields":[
                    {
                        "type":"date",
                        "title":"DOB",
                        "name":"dob"
                    },
                    {
                        "type":"toggle",
                        "title":"Keep my profile private",
                        "name":"is_private"
                    },
                ]
            },
            "xxx-times":{
                "title":"Ticket",
                "fields":[
                    {
                        "type":"datetime",
                        "title":"Arrival time",
                        "name":"arrival_time"
                    },
                    [
                        {"type":"number","title":"Quantity","name":"quantity"},
                        {"type":"currency","title":"Price","name":"price"}
                    ]
                ]
            }
        }
    }
}

我知道 PHP 中有 array_column 函数，我想使用与这个 PHP 函数等效的 javascript 函数。

任何人都可以帮助我

Answer 1

正如其他人已经说过的，JavaScript 中没有原生解决方案（作为函数）。相反，您必须使用多个步骤。您可能想要创建一些以后可以使用的通用函数。

提示：我缩短了您的示例数据以提高可读性！

var DATA = {
    "form":{
        "id":"123465",
        "title":"User Information",
        "fields":[
                    {
                        "type":"date",
                        "title":"Document date",
                        "name":"document_date",
                        "required":true
                    },
                    {
                        "type":"input",
                        "title":"Document no",
                        "name":"document_no",
                        "required":true
                    }
                ],
        "tabs":{
            // ... shortened ...
        }
    }
}



// ====== GENERAL PURPOSE FUNCTIONS ======
function prop (path, obj) {
  return path.split('.').reduce(function (p, name) {
    return p == null ? p : p[name];
  }, obj);
}

function mapMaybe (func, arr) {
  return Array.isArray(arr) ? arr.map(func) : [];
}

function mapDeep (path, func, obj) {
  return mapMaybe(func, prop(path, obj));
}



// ====== SOLUTION ======
console.log(mapDeep('form.fields', function (x) { return x.name; }, DATA))

Answer 2

没有执行深度查找的本地方法，但实际上实现起来非常简单：

//return an array of objects according to key, value, or key and value matching
function getObjects(obj, key, val) {
    var objects = [];
    for (var i in obj) {
        if (!obj.hasOwnProperty(i)) continue;
        if (typeof obj[i] == 'object') {
            objects = objects.concat(getObjects(obj[i], key, val));    
        } else 
        //if key matches and value matches or if key matches and value is not passed (eliminating the case where key matches but passed value does not)
        if (i == key && obj[i] == val || i == key && val == '') { //
            objects.push(obj);
        } else if (obj[i] == val && key == ''){
            //only add if the object is not already in the array
            if (objects.lastIndexOf(obj) == -1){
                objects.push(obj);
            }
        }
    }
    return objects;
}

//return an array of values that match on a certain key
function getValues(obj, key) {
    var objects = [];
    for (var i in obj) {
        if (!obj.hasOwnProperty(i)) continue;
        if (typeof obj[i] == 'object') {
            objects = objects.concat(getValues(obj[i], key));
        } else if (i == key) {
            objects.push(obj[i]);
        }
    }
    return objects;
}

//return an array of keys that match on a certain value
function getKeys(obj, val) {
    var objects = [];
    for (var i in obj) {
        if (!obj.hasOwnProperty(i)) continue;
        if (typeof obj[i] == 'object') {
            objects = objects.concat(getKeys(obj[i], val));
        } else if (obj[i] == val) {
            objects.push(i);
        }
    }
    return objects;
}


var json = '{"glossary":{"title":"example glossary","GlossDiv":{"title":"S","GlossList":{"GlossEntry":{"ID":"SGML","SortAs":"SGML","GlossTerm":"Standard Generalized Markup Language","Acronym":"SGML","Abbrev":"ISO 8879:1986","GlossDef":{"para":"A meta-markup language, used to create markup languages such as DocBook.","ID":"44","str":"SGML","GlossSeeAlso":["GML","XML"]},"GlossSee":"markup"}}}}}';

var js = JSON.parse(json);

//example of grabbing objects that match some key and value in JSON
console.log(getObjects(js,'ID','SGML'));
//returns 1 object where a key names ID has the value SGML

//example of grabbing objects that match some key in JSON
console.log(getObjects(js,'ID',''));
//returns 2 objects since keys with name ID are found in 2 objects

//example of grabbing obejcts that match some value in JSON
console.log(getObjects(js,'','SGML'));
//returns 2 object since 2 obects have keys with the value SGML

//example of grabbing objects that match some key in JSON
console.log(getObjects(js,'ID',''));
//returns 2 objects since keys with name ID are found in 2 objects

//example of grabbing values from any key passed in JSON
console.log(getValues(js,'ID'));
//returns array ["SGML", "44"] 

//example of grabbing keys by searching via values in JSON
console.log(getKeys(js,'SGML'));
//returns array ["ID", "SortAs", "Acronym", "str"] 

参考：http://techslides.com/how-to-parse-and-search-json-in-javascript

Answer 3

只是为以前的答案添加一个解决方案：

const data = {
  "form":{
    "id":"123465",
    "title":"User Information",
    "fields":[
      {
        "type":"date",
        "title":"Document date",
        "name":"document_date",
        "required":true
      },
      {
        "type":"input",
        "title":"Document no",
        "name":"document_no",
        "required":true
      }
    ],
    "tabs":{
      "xxx-general":{
        "title":"General",
        "fields":[
          {
            "type":"date",
            "title":"DOB",
            "name":"dob"
          },
          {
            "type":"toggle",
            "title":"Keep my profile private",
            "name":"is_private"
          },
        ]
      },
      "xxx-times":{
        "title":"Ticket",
        "fields":[
          {
            "type":"datetime",
            "title":"Arrival time",
            "name":"arrival_time"
          },
          [
            {"type":"number","title":"Quantity","name":"quantity"},
            {"type":"currency","title":"Price","name":"price"}
          ]
        ]
      }
    }
  }
};

const re = /"name"\s*:\s*"(.+?)(?<!\\)"/g;
const names = [];
const json = JSON.stringify(data);
let p;
while ((p = re.exec(json)) !== null) {
  names.push(p[1]);
}

console.log(names);