如何将所有键/值对从 forEach 推送到对象

Question

I'm running my array of objects (this.state.exportEntries) through a for loop that is then comparing the itemId to the key within the object returned within the for loop. If the key matches itemId, then run a forEach to push that key/value to the filteredData object.

My issue is that, if I have more than one value that matches, the forEach only pushes the last returned value to the filteredData object.

Could anyone help me understand how to push all returned values to the filteredData object? As you can see in the output of this.state.filteredData, only the last key/value pair that is matched gets pushed to filteredData.

Code Structure

for (let item of this.state.exportEntries) {

  console.log(item);

  Object.entries(item)
    .filter(([key,]) => key === itemId)
    .forEach(([key, value]) => (this.state.filteredData[key] = value));

}

console.log(this.state.filteredData);

Output of item

{1.2: "1", 1.3: "1"}

{1.2: "2", 1.3: "2"}

{1.2: "3", 1.3: "3"}

{1.2: "4", 1.3: "4"}

Output of this.state.filteredData

{1.3: "4"}

Desired Result

{
 1.3: "1, 2, 3, 4"
}

Answer 1

You need not to iterate the entries, because you have already a key itemId for the object.

for (let item of this.state.exportEntries) {
    console.log(item);
    if (itemId in item) {
        if (!this.state.filteredData[itemId]) this.state.filteredData[itemId] = item[itemID];
        else this.state.filteredData[itemId] += ', ' + item[itemID];
    }
}

console.log(this.state.filteredData);