[英]Iterate over an object array in JS
我有以下对象:
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}
]
我想将每个位置乘以 2,然后将它们添加到每个位置,让我解释一下:我将每个值乘以 2,这是部分结果:
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}
]
然后我必须添加每个键并通过在初始对象内的末尾添加一个新数组来添加总数,这应该是最终结果:
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
可以获得对象的所有键,使用Array.prototype.forEach
可以循环键并进行如下操作。
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()
并将结果推送到原始数组中(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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