下划线JS通过ID检索对象

Question

我有一个输入，我想通过 ID 查找对象。目前我正在 returning 这两个对象，但我想要的是，如果我搜索“01”，我只会 return 第一个对象。我已经尝试使用下划线 _.map 来执行此操作，但它没有给出我想要的结果。

var getById = function() {
    var deferred = Q.defer(),
        result;

    result = items;

    if (!result) {
        deferred.reject('item not found');
    } else {
        deferred.resolve(result);
    }

    return deferred.promise;
};

JSON:

[{
  "id": "01",
  "name": "test1",
  "orderItems": [
    {
      "productNumber": "TESTa",
      "quantity": 2,
    },
    {
      "productNumber": "TESTb",
      "quantity": 4,
    },
    {
      "productNumber": "TESTc",
      "quantity": 6,
    }
  ]
},{
  "id": "02",
  "name": "test2",
  "orderItems": [
    {
      "productNumber": "TESTe",
      "quantity": 2,
    },
    {
      "productNumber": "TESTf",
      "quantity": 7,
    },
    {
      "productNumber": "TESTg",
      "quantity": 6,
    }
  ]
}]

Answer 1

您可以使用_.filter()

Looks through each value in the list, returning an array of all the values that pass a truth test (predicate).

result = _.filter(items, function(item){
    return item.id == '01';
});

或者，_.findWhere

Looks through the list and returns the first value that matches all of the key-value pairs listed in properties.

result  = _.findWhere(items, {id : '01'});

Answer 2

var result = _.find(myItems, function(item) { return item.id === '01'; }

Answer 3

如果找到符合条件的单个项目，请使用 _.find()

It looks through each value in the list, returning the first one that passes a truth test

         var _exist = _.find(_items, function (item) {
             return item.id == your_id;
            });

如果找到所有符合条件的项目，请使用 _.filter()

It looks through each value in the list, returning an array of all the values that pass a truth test

var _exist = _.filter(_items, function (item) {
                 return item.id == your_id;
                });

在此处获取完整文档： http://underscorejs.org/

下划线JS通过ID检索对象

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