根据过滤后的对象数组中的数据创建新的对象数组

Question

I have an array of objects with a key called 'selected' which is set to false. I have a filtered array of objects from the original list where the key 'selected' is set to true. How do I create a new array where the original list is updated with true values based on the filtered list?

 const data = [{ color: "red", value: "#f00", selected: false }, { color: "green", value: "#0f0", selected: false }, { color: "blue", value: "#00f", selected: false }, { color: "cyan", value: "#0ff", selected: false }, { color: "magenta", value: "#f0f", selected: false }, { color: "yellow", value: "#ff0", selected: false }, { color: "black", value: "#000", selected: false } ] const filtered = [{ color: "magenta", value: "#f0f", selected: true }, { color: "green", value: "#0f0", selected: true }, { color: "black", value: "#000", selected: true }] const newData = data.map(item => { item.selected = filtered.find(item1 => item1.id === item.id).selected return item }) console.log(newData) 

The end result should be

    [{
        color: "red",
        value: "#f00",
        selected: false
      },
      {
        color: "green",
        value: "#0f0",
        selected: **true**
      },
      {
        color: "blue",
        value: "#00f",
        selected: false
      },
      {
        color: "cyan",
        value: "#0ff",
        selected: false
      },
      {
        color: "magenta",
        value: "#f0f",
        selected: **true**
      },
      {
        color: "yellow",
        value: "#ff0",
        selected: false
      },
      {
        color: "black",
        value: "#000",
        selected: **true**
      }
    ]

Answer 1

Store the selected color names of the filtered array in a Set. Then use the Set when mapping to decide which items are selected:

 const data = [{"color":"red","value":"#f00","selected":false},{"color":"green","value":"#0f0","selected":false},{"color":"blue","value":"#00f","selected":false},{"color":"cyan","value":"#0ff","selected":false},{"color":"magenta","value":"#f0f","selected":false},{"color":"yellow","value":"#ff0","selected":false},{"color":"black","value":"#000","selected":false}] const filtered = [{"color":"magenta","value":"#f0f","selected":true},{"color":"green","value":"#0f0","selected":true},{"color":"black","value":"#000","selected":true}] const selectedSet = new Set(filtered.map(o => o.color)) const newData = data.map(o => selectedSet.has(o.color) ? ({ ...o, selected: true }) : o) console.log(newData) 

Answer 2

You need to check color property and return a new object with a change of the property if an object is found.

 const data = [{ color: "red", value: "#f00", selected: false }, { color: "green", value: "#0f0", selected: false }, { color: "blue", value: "#00f", selected: false }, { color: "cyan", value: "#0ff", selected: false }, { color: "magenta", value: "#f0f", selected: false }, { color: "yellow", value: "#ff0", selected: false }, { color: "black", value: "#000", selected: false }], filtered = [{ color: "magenta", value: "#f0f", selected: true }, { color: "green", value: "#0f0", selected: true }, { color: "black", value: "#000", selected: true }], newData = data.map(item => { var object = filtered.find(item1 => item1.color === item.color); return Object.assign({}, item, object && { selected: object.selected }); }); console.log(newData) 

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