Stuck on Use PropTypes to Define the Props

[kaflenitish]

Tell us what’s happening:
Describe your issue in detail here.

I am getting Uncaught ReferenceError: propTypes is not defined.
I also tried using ReactDOM.render didn’t work, as I also got render error.

  **Your code so far**

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

// Change code below this line
Items.propTypes = { quantity: propTypes.number.isRequired };
// Change code above this line

Items.defaultProps = {
quantity: 0
};

class ShoppingCart extends React.Component {
constructor(props) {
  super(props);
}
render() {
  return <Items />
}
};

  **Your browser information:**

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/96.0.4664.110 Safari/537.36

Challenge: Use PropTypes to Define the Props You Expect

Link to the challenge:

freeCodeCamp.org

[jwilkins.oboe]

Hi @kaflenitish !

Look very carefully here to the issue

@kaflenitish

quantity: propTypes.number

Pay close attention to the casing in PropTypes

Once you fix that then the test will pass

[kaflenitish]

OMG. thank you so much.

 Items.propTypes = { quantity: PropTypes.number.isRequired }

so the casing on the assignment and PropTypes were different.

[lasjorg]

I found that hard to remember at first. But if you think about where the identifier proptypes is used it makes sense.

When it is a property it is camelcase so Component.propType and when it’s the type object (whatever that’s called) it is uppercase, e.g. PropTypes.func

Typechecking With PropTypes – React

[kaflenitish]

Thank you so much. This was really helpful.