如何在JavaScript中合并两个对象数组

Question

我有一个简单的问题。 我有两个数组A和B，如果B具有相同的ID，我想保留A对象。 例如：

const A = [{id: "price", value: "1"}]

const B = [{id: "price", value: "0"}, {id: "number", value: "0"}]

预期结果：

[{id: "price", value: "1"}, {id: "number", value: "0"}}]

我怎样才能做到这一点？

我试图将A和foreach B映射到A中，但它没有用。

Answer 1

const result = A.concat(B.filter(bo => A.every(ao => ao.id != bo.id)));

将来自A所有对象与来自B的不在A的对象连接起来（这通过仅过滤来自B对象来完成，其中A具有相同id的对象）。

例：

 const A = [{id: "price", value: "1"}]; const B = [{id: "price", value: "0"}, {id: "number", value: "0"}]; const result = A.concat(B.filter(bo => A.every(ao => ao.id != bo.id))); console.log(result); 

Answer 2

您在合并的数组上使用reduce - 也将value转换为数字：

 const A = [{id: "price", value: "1"}]; const B = [{id: "price", value: "0"}, {id: "number", value: "0"}]; const res = Object.values([...A, ...B].reduce((acc, { id, value }) => { if (acc[id]) acc[id].value += parseInt(value); else acc[id] = { id, value: parseInt(value) }; return acc; }, {})); console.log(res); 

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Answer 3

您可以尝试的另一个选项（我相信它将是O（n））是将数组转换为id为key的对象然后扩展（jquery.extend或pure js实现）然后将合并的对象转换回数组。

 const A = [{id: "price", value: "1"}]; const B = [{id: "price", value: "0"}, {id: "number", value: "0"}]; //convert arrays to objects var Bx = {}; B.forEach(i => Bx[i.id] = i); var Ax = {}; A.forEach(i => Ax[i.id] = i); //copy all matching id properties from A to B A.forEach(i => Bx[i.id] = Ax[i.id]); //convert the merged object to array var C = []; Object.getOwnPropertyNames(Bx).forEach(i => C.push(Bx[i])); console.log(C);