对象值的笛卡尔积（到数组）

Question

假设我有

const item = {

  "Key1": "Value1",

  "Key2": ["Value2", "Value3"]

}

如何将其转换为

[["Value1","Value2"],["Value1","Value3"]] 

？

我的做法是：

let array = [];

for (let i of item.Key2){

  array.push([item.Key1,i])

}

只是想知道还有没有更短的方法？

Answer 1

// What question mentionsconst item = {  "Key1": "Value1",  "Key2": ["Value2", "Value3"]}let res = item.Key2.map(i => [item.Key1, i])console.log(res)// What the world wants!const item = {  "Key1": ["ValueA", "ValueB"],  "Key2": ["Value1", "Value2"]}res = item.Key1.reduce((acc, i1) => acc.concat(item.Key2.map(i2 => [i1, i2])), [])console.log(res)

Answer 2

您可以构建笛卡尔积。const    item = { Key1: "Value1", Key2: ["Value2", "Value3"] },    values = Object.values(item).map(v => [].concat(v)),    result = values.reduce((a, b) => a.reduce((r, v) => r.concat(b.map(w => [].concat(v, w))), []));console.log(result);

Answer 3

const item = { Key1: "Value1", Key2: ["Value2", "Value3"]};let target = item.Key2.reduce((i, _) => {  i.push([item.Key1, _]);  return i;}, []);console.log(target)