[英]Iterate over an object array in JS
我有以下對象:
obj = [
{ 1: 20, 2: 26, 3: 14},
{ 1: 12, 2: 25, 3: 15},
{ 1: 14, 2: 13, 3: 19},
{ 1: 16, 2: 32, 3: 21}
]
我想將每個位置乘以 2,然后將它們添加到每個位置,讓我解釋一下:我將每個值乘以 2,這是部分結果:
obj = [
{ 1: 40, 2: 52, 3: 28},
{ 1: 24, 2: 50, 3: 30},
{ 1: 28, 2: 26, 3: 38},
{ 1: 32, 2: 72, 3: 42}
]
然后我必須添加每個鍵並通過在初始對象內的末尾添加一個新數組來添加總數,這應該是最終結果:
obj = [
{ 1: 20, 2: 26, 3: 14},
{ 1: 12, 2: 25, 3: 15},
{ 1: 14, 2: 13, 3: 19},
{ 1: 16, 2: 32, 3: 21},
{ 1: 104, 2: 200, 3: 138}
]
let obj = [ { 1: 20, 2: 26, 3: 14}, { 1: 12, 2: 25, 3: 15}, { 1: 14, 2: 13, 3: 19}, { 1: 16, 2: 32, 3: 21} ] let sumRow = {} let partialRes = obj.map(row => Object.keys(row).reduce((acc, key) => { acc[key] = row[key] * 2 sumRow[key] = sumRow[key] ? sumRow[key] + acc[key] : acc[key] return acc }, {})) obj.push(sumRow) console.log(obj)
使用Object.keys
可以獲得對象的所有鍵,使用Array.prototype.forEach
可以循環鍵並進行如下操作。
const input = [ { 1: 20, 2: 26, 3: 14}, { 1: 12, 2: 25, 3: 15}, { 1: 14, 2: 13, 3: 19}, { 1: 16, 2: 32, 3: 21} ]; const sumObj = {}; input.forEach((item) => { Object.keys(item).forEach((key) => { item[key] *= 2; sumObj[key] ? sumObj[key] += item[key] : sumObj[key] = item[key]; }); }); input.push(sumObj); console.log(input);
您可以使用Array.prototype.reduce()
並將結果推送到原始數組中(或以其他方式添加)
obj = [ { 1: 20, 2: 26, 3: 14}, { 1: 12, 2: 25, 3: 15}, { 1: 14, 2: 13, 3: 19}, { 1: 16, 2: 32, 3: 21} ] console.log(obj); obj.push(obj.reduce((acc, val) => ({ 1: acc[1] + val[1] * 2, 2: acc[2] + val[2] * 2, 3: acc[3] + val[3] * 2 }), {1: 0, 2: 0, 3: 0})); console.log(obj);
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