angularjs - 如何在 AngularJS 中的数组中的数组中添加值

Question

如果我的标题听起来很困惑，我深表歉意，因为我不知道如何准确地表达它。基本上，这就是我想要做的。

例如，我有以下数组:

var sourceArray = [
     { question: "Question 1", inputType: "radio", answer: "Answer 1", id: "1" },
     { question: "Question 1", inputType: "radio", answer: "Answer 2", id: "2" },
     { question: "Question 1", inputType: "radio", answer: "Answer 3", id: "3" },
     { question: "Question 2", inputType: "radio", answer: "Answer 1", id: "4" },
     { question: "Question 2", inputType: "radio", answer: "Answer 2", id: "5" },
     { question: "Question 2", inputType: "radio", answer: "Answer 3", id: "6" }
]

我想重组它，让它看起来像这样:

var newArray = [
     {
      question: "Question 1", inputType: "radio", 
      choices: [{answer: "Answer 1", id: "1"},
                {answer: "Answer 2", id: "2"},
                {answer: "Answer 3", id: "3"}
               ]},
     {
      question: "Question 2", inputType: "radio", 
      choices: [{answer: "Answer 1", id: "4"},
                {answer: "Answer 2", id: "5"},
                {answer: "Answer 3", id: "6"}
     ]}
]

答案按问题分组，因此如果 sourceArray 中的下一个问题与当前问题相同，它将把答案插入 choices 数组。

这在 AngularJS 中使用 angular.forEach 可能吗？

任何帮助将不胜感激。

一如既往地感谢您的回复。

Answer 1

给你。请参阅下面的工作示例:

// Add a hepler method in the Array to find the value
Array.prototype.find = function(key, value) {
  var index = -1;
  angular.forEach(this, function(item, i) {
    if (item[key] === value) {
      index = i;
    }
  });

  return this[index];
};

var app = angular.module("sa", []);

app.controller("FooController", function($scope) {

  $scope.sourceArray = [{
    question: "Question 1",
    inputType: "radio",
    answer: "Answer 1",
    id: "1"
  }, {
    question: "Question 1",
    inputType: "radio",
    answer: "Answer 2",
    id: "2"
  }, {
    question: "Question 1",
    inputType: "radio",
    answer: "Answer 3",
    id: "3"
  }, {
    question: "Question 2",
    inputType: "radio",
    answer: "Answer 1",
    id: "4"
  }, {
    question: "Question 2",
    inputType: "radio",
    answer: "Answer 2",
    id: "5"
  }, {
    question: "Question 2",
    inputType: "radio",
    answer: "Answer 3",
    id: "6"
  }];

  $scope.newArray = [];

  $scope.convert = function() {
    // Iterate array
    angular.forEach($scope.sourceArray, function(item) {
      // Check if the question alrady exists
      if (!$scope.newArray.find('question', item.question)) {
        // If not, push the question to the array with empty choices
        $scope.newArray.push({
          question: item.question,
          inputType: item.inputType,
          choices: []
        });
      }

      var newArrayItem = $scope.newArray.find('question', item.question);
      
      // Push the choices
      newArrayItem.choices.push({
        answer: item.answer,
        id: item.id
      });
    });
  };
});

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css" integrity="sha384-1q8mTJOASx8j1Au+a5WDVnPi2lkFfwwEAa8hDDdjZlpLegxhjVME1fgjWPGmkzs7" crossorigin="anonymous">


<div ng-app="sa" ng-controller="FooController">
  Before:
  <br>{{sourceArray | json}}
  <br>
  <a href="" ng-click="convert()">convert</a>
  <br>After:
  <br>{{newArray | json}}
</div>