深度展平对象中的数组字段

Question

我有一个对象，它有一些字段是数组(字符串或其他对象(，我试图将此对象转换为csv，但对于具有数组的情况，我希望csv在数组的情况下是垂直的(而不是水平的，并将索引附加到字段名(。在尝试了几个npm库和在线转换器后，我无法实现我想要的，带有数组的字段只是用它们的索引作为列名编写的。

作为一种变通方法，我现在试图将对象展平以充实数组字段，然后将其转换为csv，但展平仍然保持数组原样，输出中的对象数量没有变化。我尝试过lodash、下划线、Array的flat等库，但都没有成功。

有没有一种方法可以实现这一点，要么直接转换为csv，要么至少将对象变平。

我的实物样本低于

[
{
"field1": "Hello",
"field2": [
"list item 1",
"list item 2",
"list item 3"
],
"field3": [],
"field4": [{
"subfield1": "World",
"subfield2": "!"
}, {
"subfield1": "Again",
"subfield2": "?"
}]
}
]

基于这个示例对象，我的输出应该是.

[
{
"field1": "Hello",
"field2": "list item 1",
"field3": null, // or [], in this case it wouldn't matter
"field4": {
"subfield1": "World",
"subfield2": "!"
}
},
{
"field1": "Hello",
"field2": "list item 1",
"field3": null,
"field4": {
"subfield1": "Again",
"subfield2": "?"
}
},
{
"field1": "Hello",
"field2": "list item 2",
"field3": null,
"field4": {
"subfield1": "World",
"subfield2": "!"
}
},
{
"field1": "Hello",
"field2": "list item 2",
"field3": null,
"field4": {
"subfield1": "Again",
"subfield2": "?"
}
},
{
"field1": "Hello",
"field2": "list item 3",
"field3": null,
"field4": {
"subfield1": "World",
"subfield2": "!"
}
},
{
"field1": "Hello",
"field2": "list item 3",
"field3": null,
"field4": {
"subfield1": "Again",
"subfield2": "?"
}
}
]

有没有什么图书馆可以让我做到这一点？

Answer 1

除了空数组之外，您可以对所有值使用笛卡尔乘积。

function getCartesian(object) {
return Object.entries(object).reduce((r, [k, v]) => {
const temp = [];
if (Array.isArray(v) && !v.length) v = null;
r.forEach(s =>
(Array.isArray(v) ? v : [v]).forEach(w =>
(w && typeof w === 'object' ? getCartesian(w) : [w]).forEach(x =>
temp.push(Object.assign({}, s, { [k]: x }))
)
)
);
return temp;
}, [{}]);
}
const
data = { field1: "Hello", field2: ["list item 1", "list item 2", "list item 3"], field3: [], field4: [{ subfield1: "World", subfield2: "!" }, { subfield1: "Again", subfield2: "?" }] },
result = getCartesian(data);
console.log(result);

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