freeCodeCamp/curriculum/challenges/english/03-front-end-development-libraries/react/override-default-props.md

---
id: 5a24c314108439a4d403616c
title: Override Default Props
challengeType: 6
forumTopicId: 301399
dashedName: override-default-props
---

# --description--

The ability to set default props is a useful feature in React. The way to override the default props is to explicitly set the prop values for a component.

# --instructions--

The `ShoppingCart` component now renders a child component `Items`. This `Items` component has a default prop `quantity` set to the integer `0`. Override the default prop by passing in a value of `10` for `quantity`.

**Note:** Remember that the syntax to add a prop to a component looks similar to how you add HTML attributes. However, since the value for `quantity` is an integer, it won't go in quotes but it should be wrapped in curly braces. For example, `{100}`. This syntax tells JSX to interpret the value within the braces directly as JavaScript.

# --hints--

The component `ShoppingCart` should render.

```js
assert(
  (function () {
    const mockedComponent = Enzyme.mount(React.createElement(ShoppingCart));
    return mockedComponent.find('ShoppingCart').length === 1;
  })()
);
```

The component `Items` should render.

```js
assert(
  (function () {
    const mockedComponent = Enzyme.mount(React.createElement(ShoppingCart));
    return mockedComponent.find('Items').length === 1;
  })()
);
```

The `Items` component should have a prop of `{ quantity: 10 }` passed from the `ShoppingCart` component.

```js
(getUserInput) =>
  assert(
    (function () {
      const mockedComponent = Enzyme.mount(React.createElement(ShoppingCart));
      return (
        mockedComponent.find('Items').props().quantity == 10 &&
        getUserInput('index')
          .replace(/ /g, '')
          .includes('<Itemsquantity={10}/>')
      );
    })()
  );
```

# --seed--

## --after-user-code--

```jsx
ReactDOM.render(<ShoppingCart />, document.getElementById('root'))
```

## --seed-contents--

```jsx
const Items = (props) => {
  return <h1>Current Quantity of Items in Cart: {props.quantity}</h1>
}

Items.defaultProps = {
  quantity: 0
}

class ShoppingCart extends React.Component {
  constructor(props) {
    super(props);
  }
  render() {
    { /* Change code below this line */ }
    return <Items />
    { /* Change code above this line */ }
  }
};
```

# --solutions--

```jsx
const Items = (props) => {
  return <h1>Current Quantity of Items in Cart: {props.quantity}</h1>
}

Items.defaultProps = {
  quantity: 0
}

class ShoppingCart extends React.Component {
  constructor(props) {
    super(props);
  }
  render() {
    { /* Change code below this line */ }
    return <Items quantity = {10} />
    { /* Change code above this line */ }
  }
};
```