的Javascript合并

Question

我有以下形式

"myData": [{ 
    "items": [{ 
     "attr1": "someInfoBatch1", 
     "attr2": "someOtherInfoBatch1" 
    }], 
    "someStates": [ "STATE_PASS_1" ] 
},{ 
    "items": [{ 
     "attr1": "someInfoBatch2", 
     "attr2": "someOtherInfoBatch2" 
    }], 
    "someStates": [ "STATE_PASS_1", "STATE_FAILED_1" ] 
}] 

现在我想基于值someStates

所以合并myData.items数组的myData如果someStates包含通在一个批次&其他失败一批（即说STATE_FAILED_1），我想myData.items是独立的（即myData.item[0] & myData.item[1]）

但是让我们假设在上面的例子中someStates只包含如下的传递状态;对于第一批"someStates":["STATE_PASS_1"] &为第二批"someStates":["STATE_PASS_1", "STATE_PASS_2"]

在上述情况下，我需要myData.items合并成如下面的单个阵列;

"items": [{ 
    "attr1": "someInfoBatch1", 
    "attr2": "someOtherInfoBatch1" 
},{ 
    "attr1": "someInfoBatch2", 
    "attr2": "someOtherInfoBatch2" 
}] 

Answer 1

可以用下划线做这样一行：_.pluck(myData, "items")

看到http://underscorejs.org/#pluck

Answer 2

分解undescore.js：

// Return the results of applying the iteratee to each element. 
    var map = function(obj, iteratee, context) { 
    iteratee = cb(iteratee, context); 
    var keys = !isArrayLike(obj) && _.keys(obj), 
     length = (keys || obj).length, 
     results = Array(length); 
    for (var index = 0; index < length; index++) { 
     var currentKey = keys ? keys[index] : index; 
     results[index] = iteratee(obj[currentKey], currentKey, obj); 
    } 
    return results; 
    }; 

    var property = function(key) { 
    return function(obj) { 
     return obj == null ? void 0 : obj[key]; 
    }; 
    }; 

和呼叫：var items = map(myData, property("items"));

Answer 3

你可以只需使用Array#map为它。

var $scope = { "myData": [{ "items": [{ "attr1": "someInfoBatch1", "attr2": "someOtherInfoBatch1" }], "someStates": ["STATE_PASS_1"] }, { "items": [{ "attr1": "someInfoBatch2", "attr2": "someOtherInfoBatch2" }], "someStates": ["STATE_PASS_1", "STATE_FAILED_1"] }] }, 
 
    items = $scope.myData.map(function (a) { 
 
     return a.items[0]; 
 
    }); 
 

 
console.log(items);

ES6

var $scope = { "myData": [{ "items": [{ "attr1": "someInfoBatch1", "attr2": "someOtherInfoBatch1" }], "someStates": ["STATE_PASS_1"] }, { "items": [{ "attr1": "someInfoBatch2", "attr2": "someOtherInfoBatch2" }], "someStates": ["STATE_PASS_1", "STATE_FAILED_1"] }] }, 
 
    items = $scope.myData.map(a => a.items[0]); 
 

 
console.log(items);