根据动态传递的属性从对象数组中获取唯一值

Question

I have this scenario where I need to fetch unique values of all objects based on a dynamically passed property . I have tried the following approach but does not seem like working.

var arr = [
  {
    id: "1",
    type: "x",
    source: {
      val1: "3",
      val2: "4",
      val3: "6",
    },
  },
  {
    id: "1",
    type: "x",
    source: {
      val1: "3",
      val2: "4",
      val3: "6",
    },
  },
  {
    id: "1",
    type: "x",
    source: {
      val1: "4",
      val2: "5",
      val3: "6",
    }
  }
];

Now say I pass val1 it should give me unique values 3,4 and if I pass val2 it should give me 4,5. PS : I will only pass the parameter that are present inside source property.

Approach that I have tried:

 calculate = (param) =>
 {
   let uniqueValues = Array.from(
        new Set(arr.map((arr: any) => arr[param]))
   );
 }

Answer 1

看起来，您也需要source属性。

new Set(arr.map((o: any) => o.source[param]))

Answer 2

You can use map to get source values and then reduce inuque values:

 const arr = [ { id: "1", type: "x", source: { val1: "3", val2: "4", val3: "6", }, }, { id: "1", type: "x", source: { val1: "3", val2: "4", val3: "6", }, }, { id: "1", type: "x", source: { val1: "4", val2: "5", val3: "6", } } ]; function calculate(data, param) { return data.map(x => { return (x.source || {})[param]; }).reduce((acc, val) => { if (acc.indexOf(val) === -1) acc.push(val); return acc; }, []); } console.log(calculate(arr, "val1")); console.log(calculate(arr, "val2"));