How to merge array of objects with same key

Question

I have one array with multiple object,want to merge them by same keys without losing their values.

I try some of answer in stakoverflow but none of them help me.i want to do this with map/reduce but i don't know how can i retrieve key name of every object to check them.

let rows = [
  { row1: [{ val: "row1-val1" }, { val: "row1-val2" }] },
  { row1: [{ val: "row1-val3" }, { val: "row1-val4" }] },
  { row1: [{ val: "row1-val5" }, { val: "row1-val6" }] },
  { parag: { text: "sample test" } },
  { row2: [{ val: "row2-val1" }, { val: "row2-val2" }] },
  { row2: [{ val: "row2-val3" }, { val: "row2-val4" }] },
  { row2: [{ val: "row2-val5" }, { val: "row2-val6" }] }
];

i want this result:

let rows = [
  {
    row1: [
      { val: "row1-val1" },
      { val: "row1-val2" },
      { val: "row1-val3" },
      { val: "row1-val4" },
      { val: "row1-val5" },
      { val: "row1-val6" }
    ]
  },
  { parag: { text: "sample test" } },
  {
    row2: [
      { val: "row2-val1" },
      { val: "row2-val2" },
      { val: "row2-val3" },
      { val: "row2-val4" },
      { val: "row2-val5" },
      { val: "row2-val6" }
    ]
  }
];

Answer 1

You can do it with help of reduce

 let rows = [{ row1: [{ val: "row1-val1" }, { val: "row1-val2" }] },{ row1: [{ val: "row1-val3" }, { val: "row1-val4" }] },{ row1: [{ val: "row1-val5" }, { val: "row1-val6" }] },{ parag: { text: "sample test" } },{ row2: [{ val: "row2-val1" }, { val: "row2-val2" }] },{ row2: [{ val: "row2-val3" }, { val: "row2-val4" }] },{ row2: [{ val: "row2-val5" }, { val: "row2-val6" }] }]; let op = rows.reduce((o,c)=>{ let key = Object.keys(c)[0]; if(o[key]){ o[key].push(...c[key]); } else { o[key] = c[key]; } return o; },{}) console.log(op)