How Do You Update Nested State in React Using the Imperative Approach?

Imperative Approach to Updating Nested State

In React, state updates are immutable. This means that to update a nested object or array, you cannot simply modify its properties and expect the changes to be reflected in the UI. Instead, you need to create a new object or array that includes the updated values and then pass it to setState.

Consider the following example, where we want to update the name property of the object at index 1 in the items array stored in state:

<code class="javascript">handleChange: function (e) {
  // Make a copy of the items array
  let items = [...this.state.items];

  // Make a copy of the item object at index 1
  let item = {...items[1]};

  // Change the name property of the copied item
  item.name = 'New Name';

  // Replace the item at index 1 with the updated item
  items[1] = item;

  // Update the state with the new items array
  this.setState({items});
},</code>

In this approach, we use spread syntax (...) to create shallow copies of the items array and the item object at index 1. We then modify the name property of the copied item and replace the item at index 1 with the updated version. Finally, we update the state with the new items array.

This approach is straightforward and works well for simple state updates. However, it can become cumbersome and error-prone for complex state updates involving multiple nested objects or arrays.

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