Why does this work?

JavaScript
#1

Tell us what’s happening:
my code works

i was trying to test what an error would look like if i input the wrong type of input, but it compiled

why?

Your code so far


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

// change code below this line

//import PropTypes from 'prop-types';
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 quantity={'dude'}/>
}
};

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/79.0.3945.130 Safari/537.36.

Challenge: Use PropTypes to Define the Props You Expect

Link to the challenge:
https://www.freecodecamp.org/learn/front-end-libraries/react/use-proptypes-to-define-the-props-you-expect

#2

It should “compile” (it isn’t really compiling anything, but I guess can treat is doing that)

a. The error warning only appears in the browser console
b. On a phone so can’t check this, but only appears using a development build in a development environment, and depending how the very specific test environment has been set up on FCC, it might not error anyway

#3