我有一个像这样的数组
[
{
item_guid: "57e7a1cd6a3f3669dc03db58"
quantity:3
},
{
item_guid: "57e77b06e0566d496b51fed5"
quantity:3
},
{
item_guid: "57e7a1cd6a3f3669dc03db58"
quantity:3
},
{
item_guid: "57e77b06e0566d496b51fed5"
quantity:3
}
]
我想从这里将类似的item_guid
合并到一个对象中,数量总结如下
[
{
item_guid: "57e7a1cd6a3f3669dc03db58"
quantity:6
},
{
item_guid: "57e77b06e0566d496b51fed5"
quantity:6
}
]
我知道这可以实现一些循环,而不是寻找使用lodash或EcmaScript2015代码的解决方案来让我们的生活更轻松
答案 0 :(得分:4)
一种简单的方法:
循环数据并创建一个对象,其中key将是唯一ID,其值将是数量。然后循环回对象的键并创建对象。
var data = [{ item_guid: "57e7a1cd6a3f3669dc03db58", quantity: 3 }, { item_guid: "57e77b06e0566d496b51fed5", quantity: 3 }, { item_guid: "57e7a1cd6a3f3669dc03db58", quantity: 3 }, { item_guid: "57e77b06e0566d496b51fed5", quantity: 3 }],
var r = {};
data.forEach(function(o){
r[o.item_guid] = (r[o.item_guid] || 0) + o.quantity;
})
var result = Object.keys(r).map(function(k){
return { item_guid: k, quantity: r[k] }
});
console.log(result)
答案 1 :(得分:2)
普通Javascript中的解决方案,其中包含item_guid
的哈希表。
var data = [{ item_guid: "57e7a1cd6a3f3669dc03db58", quantity: 3 }, { item_guid: "57e77b06e0566d496b51fed5", quantity: 3 }, { item_guid: "57e7a1cd6a3f3669dc03db58", quantity: 3 }, { item_guid: "57e77b06e0566d496b51fed5", quantity: 3 }],
grouped = data.reduce(function (hash) {
return function (r, a) {
(hash[a.item_guid] = hash[a.item_guid] || r[r.push({ item_guid: a.item_guid, quantity: 0 }) - 1]).quantity += a.quantity;
return r;
};
}(Object.create(null)), []);
console.log(grouped);

ES6
var data = [{ item_guid: "57e7a1cd6a3f3669dc03db58", quantity: 3 }, { item_guid: "57e77b06e0566d496b51fed5", quantity: 3 }, { item_guid: "57e7a1cd6a3f3669dc03db58", quantity: 3 }, { item_guid: "57e77b06e0566d496b51fed5", quantity: 3 }],
grouped = data.reduce((map => (r, a) => {
map.set(a.item_guid, map.get(a.item_guid) || r[r.push({ item_guid: a.item_guid, quantity: 0 }) - 1]);
map.get(a.item_guid).quantity += a.quantity;
return r;
})(new Map), []);
console.log(grouped);

答案 2 :(得分:1)
你可以
item_guid
这样的事情:
var result = _.chain(data)
.groupBy('item_guid')
.map(function(objects, guid) {
return {
item_guid: guid,
quantity: _.sumBy(objects, 'quantity')
};
})
.value();
和演示
var data = [
{
item_guid: "57e7a1cd6a3f3669dc03db58",
quantity:3
},
{
item_guid: "57e77b06e0566d496b51fed5",
quantity:3
},
{
item_guid: "57e7a1cd6a3f3669dc03db58",
quantity:3
},
{
item_guid: "57e77b06e0566d496b51fed5",
quantity:3
}
];
var result = _.chain(data)
.groupBy('item_guid')
.map(function(objects, guid) {
return {
item_guid: guid,
quantity: _.sumBy(objects, 'quantity')
};
})
.value();
console.log(result);
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.16.4/lodash.min.js"></script>
答案 3 :(得分:0)
var groupedItems = [];
var totalItems = [{item_guid: "57e7a1cd6a3f3669dc03db58", quantity:3},{item_guid: "57e77b06e0566d496b51fed5",quantity:3}, { item_guid: "57e7a1cd6a3f3669dc03db58", quantity:3 }, { item_guid: "57e77b06e0566d496b51fed5", quantity:3}];
totalItems.forEach((e) => {
if (groupedItems.findIndex(x => x.item_guid === e.item_guid) < 0) {
let totalQuantity = totalItems
.filter(x => x.item_guid === e.item_guid)
.map(x => x.quantity)
.reduce(function(a, b) { return a + b;});
groupedItems.push({item_guid: e.item_guid, quantity: totalQuantity})
}
})
console.log(groupedItems);