Question

我想要执行下面的转换，但我遇到了如何做的麻烦，只是想知道是否有人有任何指针：

//Source
[ 
   { types: ['a', 'b'] }, 
   { types: ['b'] }, 
   { types: ['a', 'c'] } 
]
//Transformation
{ 
   'a': [ { types: ['a', 'b'] }, { types: ['a', 'c'] }  ], 
   'b': [ { types: ['a', 'b'] }, { types: ['b'] } ],
   'c': [ { types: ['a', 'c'] } ]
}

Answer 1

将 reduce() 与 forEach()

一起使用

＆＃13;

var data = [{
  types: ['a', 'b']
}, {
  types: ['b']
}, {
  types: ['a', 'c']
}];

var res = data.reduce(function(a, b) {
  b.types.forEach(function(v) { // iterate over inner array
    a[v] = a[v] || []; // define the property if not defined
    a[v].push(b); // push the object refence 
  });
  return a;
}, {});

document.write('<pre>' + JSON.stringify(res, 0, 3) + '</pre>');

＆＃13;

对于旧浏览器，请检查forEch和reduce方法的填充选项。

Answer 2

我们可以使用数组＆amp;的(function () { 'use strict'; angular .module('myapp') .factory('myFactory', ServiceFactory); myFactory.$inject = ['$http', '$rootScope']; var config = { // TO DO : check if anything required }; /* @ngInject */ function myFactory($http, $rootScope) { var userName = null; var userId = null; var pwd = null; var service = { getUserName: getUserName, setUserName: setUserName, getPwd:getPwd, setPwd:setPwd, }; function getUserName() { console.log("user name.getUserName." + userName); return userName; } function setUserName(userName) { console.log("user name.." + userName); userName = userName; } function getPwd() { console.log("user getPwd.." + pwd); return pwd; } function setPwd(pwd) { console.log("user setPwd.." + pwd); pwd = pwd; } return service; } })();迭代

.reduce

Answer 3

＆＃13;

    var data = [{
      types: ['a', 'b']
    }, {
      types: ['b']
    }, {
      types: ['a', 'c']
    }];

    var transform = function(records) {
    	var obj = {};
    	
    	records.forEach(function(record){
    		record.types.forEach(function(value){
                    obj[value] = obj[value] || []
    		    obj[value].push(record);
    		});
    	});
    
    	return obj;	
    };

    document.write('<pre>' + JSON.stringify(transform(data)) + '</pre>');

＆＃13;

IndexBy类型为array的嵌套对象值

3 个答案: