React/JavaScript: Adding property to nested array in state in React

Question

I need to add an id number to the nested array in data called action. The code I'm using is:

const { data } = this.state
        const newData = Object.assign([...data.action], Object.assign([...data.action],{0:'id' }))

but this code is not working. The result I am looking for is: {id:1 action: "user...}

vijayst · Accepted Answer · 2018-09-02 07:00:45Z

2

You can just use the spread operator.

const newData = {
  ...data,
  action: {
    ...data.action,
    id: 1
  }
};

If action is an array, you can try something like this:

const newAction = data.action.map((actionItem, index) => ({
  ...actionItem,
  id: index + 1
}));
const newData = {
  ...data,
  action: newAction
};

answered Sep 2, 2018 at 6:31

vijayst

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10 Comments

How do I make id add +1 for each item in the array?

This was helpful but I need id inside the array objects that inside action.

Now it says id: NaN

Maybe, it is undefined. Try id: typeof actionItem.id === 'undefined' ? 1 : actionItem.id + 1

And I need it to be the first property in the array.

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