如何將JSON對象與相同的鍵並添加其他相應的值？

Question

我試過下面的代碼。

var SeatWithCat = [{ 
    "level": "Level II", 
    "price": 5, 
    "quantity": 1, 
    "seats": "B3" 
}, { 
    "level": "Level II", 
    "price": 5, 
    "quantity": 1, 
    "seats": "B1" 
}, { 
    "level": "Level I", 
    "price": 10, 
    "quantity": 1, 
    "seats": "A2" 
}, { 
    "level": "Level III", 
    "price": 30, 
    "quantity": 1, 
    "seats": "C1" 
}, { 
    "level": "Level III", 
    "price": 30, 
    "quantity": 1, 
    "seats": "C2" 
}, { 
    "level": "Level V", 
    "price": 50, 
    "quantity": 1, 
    "seats": "E1" 
}, { 
    "level": "Level II", 
    "price": 5, 
    "quantity": 1, 
    "seats": "B2" 
}, { 
    "level": "Level VI", 
    "price": 2, 
    "quantity": 1, 
    "seats": "F1" 
}]; 
var temp = []; 
var jsonarr = []; 
for (var i = 0; i < SeatWithCat.length; i++) { 
    for (var j = 1; j < SeatWithCat.length; j++) { 
    if (SeatWithCat[i].level === SeatWithCat[j].level) { 
     temp.push({ 
     level: SeatWithCat[i].level, 
     quantity: SeatWithCat[i].quantity + SeatWithCat[j].quantity, 
     price: SeatWithCat[i].price + SeatWithCat[j].price, 
     seats: SeatWithCat[i].seats + "," + SeatWithCat[j].seats 
     }); 
     SeatWithCat = SeatWithCat.filter(function(el) { 
     return el.level !== SeatWithCat[i].level; 
     }); 
     jsonarr = SeatWithCat; 
     alert(JSON.stringify(temp)); 
    } 
    } 
} 
var finalObj = temp.concat(jsonarr); 
alert(JSON.stringify(finalObj)); 

輸出：

[{ 
    "level": "Level II", 
    "quantity": 2, 
    "price": 10, 
    "seats": "B3,B1" 
}, { 
    "level": "Level III", 
    "quantity": 2, 
    "price": 60, 
    "seats": "C1,C1" 
}, { 
    "level": "Level VI", 
    "quantity": 2, 
    "price": 4, 
    "seats": "F1,F1" 
}, { 
    "level": "Level I", 
    "price": 10, 
    "quantity": 1, 
    "seats": "A2" 
}, { 
    "level": "Level V", 
    "price": 50, 
    "quantity": 1, 
    "seats": "E1" 
}] 

它的正常工作具有同等水平的兩個對象，但如果與同級別的陣列中有兩個以上的物體其無法正常工作。我的要求是爲任何數量的具有相同級別的對象添加值。 在此先感謝！

Answer 1

您可以使用Array.prototype.reduce()收集在字典中的唯一項目，然後轉換字典回陣列使用Array.prototype.map()：

function combine(arr) { 
 
    var combined = arr.reduce(function(result, item) { 
 
    var current = result[item.level]; 
 

 
    result[item.level] = !current ? item : { 
 
     level: item.level, 
 
     price: current.price + item.price, 
 
     quantity: current.quantity + item.quantity, 
 
     seats: current.seats + ',' + item.seats 
 
    }; 
 

 
    return result; 
 
    }, {}); 
 

 
    return Object.keys(combined).map(function(key) { 
 
    return combined[key]; 
 
    }); 
 
} 
 

 
var SeatWithCat = [{"level":"Level II","price":5,"quantity":1,"seats":"B3"},{"level":"Level II","price":5,"quantity":1,"seats":"B1"},{"level":"Level I","price":10,"quantity":1,"seats":"A2"},{"level":"Level III","price":30,"quantity":1,"seats":"C1"},{"level":"Level III","price":30,"quantity":1,"seats":"C2"},{"level":"Level V","price":50,"quantity":1,"seats":"E1"},{"level":"Level II","price":5,"quantity":1,"seats":"B2"},{"level":"Level VI","price":2,"quantity":1,"seats":"F1"}]; 
 

 
var result = combine(SeatWithCat); 
 

 
console.log(result);

Answer 2

你可以使用一個哈希表作爲參考結果集中的同一級別對象。

迭代數組並檢查散列 - 如果未設置，則使用實際屬性生成新對象。否則，請添加quantity並附加seats。

該建議只使用一個循環。

var seatWithCat = [{ level: "Level II", price: 5, quantity: 1, seats: "B3" }, { level: "Level II", price: 5, quantity: 1, seats: "B1" }, { level: "Level I", price: 10, quantity: 1, seats: "A2" }, { level: "Level III", price: 30, quantity: 1, seats: "C1" }, { level: "Level III", price: 30, quantity: 1, seats: "C2" }, { level: "Level V", price: 50, quantity: 1, seats: "E1" }, { level: "Level II", price: 5, quantity: 1, seats: "B2" }, { level: "Level VI", price: 2, quantity: 1, seats: "F1" }], 
 
    result = []; 
 

 
seatWithCat.forEach(function (o) { 
 
    if (!this[o.level]) { 
 
     this[o.level] = { level: o.level, price: o.price, quantity: o.quantity, seats: o.seats }; 
 
     result.push(this[o.level]); 
 
     return; 
 
    } 
 
    this[o.level].quantity += o.quantity; 
 
    this[o.level].seats += ',' + o.seats; 
 
}, Object.create(null)); 
 

 
console.log(result);

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Answer 3

我強烈建議使用lodash和工具他們精彩的瑞士軍刀，而不是寫你自己的。你可能需要更多。 https://lodash.com/docs/4.16.4