如何在 myArray 的 Javascript 中创建一个包含嵌套数组的数组？

Question

I need to split riskTypeNo from each object and then assign selectedValue to each value and then create an array with all the objects. With my code I am getting nested arrays

    const myArray = [
  {
    "fieldID": 1681977,
    "riskTypeNo": "A1;M1",
    "selectedValue": "4"
  },
  {
    "fieldID": 1681984,
    "riskTypeNo": "C6;M1",
    "selectedValue": "1"
  },
  {
    "fieldID": 1682084,
    "riskTypeNo": "A13;C6;M1;D5",
    "selectedValue": "3"
  }
];


console.log(
    myArray.map(item1 => {
    const riskTypeNo =  item1.riskTypeNo.split(";").map(item2 => ({ "riskTypeNo": item2,  "selectedValue": item1.selectedValue }));
    return riskTypeNo;   
  })
);

Desired Result is:

[ 
{ riskTypeNo: "A1", selectedValue: "4" }, { riskTypeNo: "M1", selectedValue: "4" }], [{ riskTypeNo: "C6", selectedValue: "1" }, { riskTypeNo: "M1", selectedValue: "1" }], [{ riskTypeNo: "A13", selectedValue: "3" }, { riskTypeNo: "C6", selectedValue: "3" }, { riskTypeNo: "M1", selectedValue: "3" }, { riskTypeNo: "D5", selectedValue: "3" } 
}]

Answer 1

You can return the split array from inside the map method. But that will get you an array of arrays. To flatten those arrays just use the array method flat .

This should work:

const result = myArray.map(el => {
    const riskTypes = el.riskTypeNo.split(";").map(riskTypeNo => ({
        riskTypeNo,
        selectedValue: el.selectedValue,
    }))
    return riskTypes;                                           
}).flat();

Answer 2

Here's one way:

 const myArray = [ { "fieldID": 1681977, "riskTypeNo": "A1;M1", "selectedValue": "4" }, { "fieldID": 1681984, "riskTypeNo": "C6;M1", "selectedValue": "1" }, { "fieldID": 1682084, "riskTypeNo": "A13;C6;M1;D5", "selectedValue": "3" } ]; const result = myArray.reduce((prev,cur) => { let obj = []; cur.riskTypeNo.split(';').forEach((n) => { obj.push({riskTypeNo: n, selectedValue: cur.selectedValue}); }); prev.push(...obj); return prev; }, []); console.log(result);

Answer 3

you can use this method instead :

const newArray = [];
myArray.forEach((item1) => {
  item1.riskTypeNo.split(";").forEach((item2) => {
    newArray.push({ riskTypeNo: item2, selectedValue: item1.selectedValue });
  });
});

result will be in newArray .