Removing from React.js array state without mutation

React.js is a popular JavaScript library for building user interfaces. One common task when working with React is updating the state of an array without mutating the original array. In this article, we will explore how to remove items from a React.js array state without mutating it.

Using the filter method

One approach to removing items from a React.js array state without mutation is to use the filter method. This method creates a new array with all elements that pass the test implemented by the provided function. Here’s an example of how to remove an item from a React.js array state using the filter method:

        
          const [items, setItems] = useState([1, 2, 3, 4, 5]);

          const removeItem = (itemToRemove) => {
            const updatedItems = items.filter(item => item !== itemToRemove);
            setItems(updatedItems);
          }
        
      

In the example above, we use the filter method to create a new array updatedItems that does not contain the item to be removed. We then use the setItems function to update the array state with the new array.

Using the spread operator

Another approach to removing items from a React.js array state without mutation is to use the spread operator. The spread operator allows us to create a new array with the elements of an existing array. Here’s an example of how to remove an item from a React.js array state using the spread operator:

        
          const [items, setItems] = useState([1, 2, 3, 4, 5]);

          const removeItem = (itemToRemove) => {
            const updatedItems = items.filter(item => item !== itemToRemove);
            setItems([...updatedItems]);
          }
        
      

In this example, we use the spread operator [...updatedItems] to create a new array with the elements of the updatedItems array. We then use the setItems function to update the array state with the new array.

Conclusion

When working with React.js, it’s important to update array state without mutating the original array. By using the filter method or the spread operator, we can remove items from a React.js array state without mutation, ensuring that our application remains predictable and easier to maintain.