How to add a new key value to react js state array?

Question

I want to add new key value to array ınto state? I tell you what I want to do below. How can I do that? 1. Start state in consruture method

`this.state = {
    files: []
}'

2. After I doing set state with active files

   this.setState({files: activeFiles})

3. Screen my state

   { files: [ { key1: val1, key2: val2, key3: val3 }, { key1: val1, key2: val2, key3: val3 }, { key1: val1, key2: val2, key3: val3 } ] }

4. How to add new key value for each file? The state I want

   { files: [ { key1: val1, key2: val2, key3: val3, key4: val4 }, { key1: val1, key2: val2, key3: val3, key4: val4 }, { key1: val1, key2: val2, key3: val3, key4: val4 } ] }

Answer 1

I think This will meet the above scenario.

const newFile = this.state.files.map((file) => {

    return {...file, key4: val4};
});
this.setState({files: newFile });