在 json 数组 javascript 中组合相同的对象

Question

I have this array:

[{ "id": 1, "myId": "100", "name": "amey" }, { "id": 2, "myId": "100", "name": "anuj" }, { "id": 3, "myId": "101", "name": "suraj" }, { "id": 4, "myId": "101", "name": "suraj h" }]

I want output like this:

[{ "id": 1, "myId": "100", "name": ["amey", "anuj"] }, { "id": 3, "myId": "101", "name": ["suraj", "suraj h] }]

How can I do this using javascript

for (var i = 0; i < myarray.length; i++) {
  //And loop again for duplicate data
  for (var j = i + 1; j < myarray.length; j++) {
    if (
      myarray[i].VENDOR_ID == myarray[j].VENDOR_ID &&
      myarray[i].ORDER_ID === myarray[j].ORDER_ID
    ) {
      var tmp = myarray[j].NAME;
      console.log(tmp);
      myarray[j].NAME = [];
      myarray[j].NAME.push(tmp);
      myarray[j].NAME.push(myarray[i].NAME);
      myarray[i] = {};
    }
  }
}

Answer 1

You can use Array.prototype.reduce() :

 const arr1 = [{ "id": 1, "myId": "100", "name": "amey" }, { "id": 2, "myId": "100", "name": "anuj" }, { "id": 3, "myId": "101", "name": "suraj" }, { "id": 4, "myId": "101", "name": "suraj h" }] const reduced = arr1.reduce((acc, item) => { // 1. check if the 'acc' array already contains an item with the same 'myId' attribute const itemIndex = acc.findIndex(it => it.myId === item.myId); // 2. if there isn't any, push into the 'acc' array a copy of the item, // with the 'name' property converted into an array of strings // otherwise simply push the 'name' into the already existing item if (itemIndex === -1) { acc.push({...item, name: [item.name] }); } else { acc[itemIndex].name.push(item.name) } return acc; }, []); // test console.log(reduced);

Answer 2

You can use an array reduce into an object and return the array of values. Reduce into an object using the myId property as the key to group by. Shallow copy any existing state and and name array, appending the new name value from the current element.

Object.values(
  input.reduce(
    (acc, { id, myId, name }) => ({
      ...acc,
      [myId]: {
        ...(acc[myId] || { id, myId }),
        name: [...(acc[myId]?.name || []), name]
      }
    }),
    {}
  )

 const input = [ { id: 1, myId: "100", name: "amey" }, { id: 2, myId: "100", name: "anuj" }, { id: 3, myId: "101", name: "suraj" }, { id: 4, myId: "101", name: "suraj h" } ]; const res = Object.values( input.reduce( (acc, { id, myId, name }) => ({...acc, [myId]: {...(acc[myId] || { id, myId }), name: [...(acc[myId]?.name || []), name] } }), {} ) ); console.log(JSON.stringify(res));