The previous challenges covered a lot about creating and composing JSX elements, functional components, and ES6 style class components in React. With this foundation, it's time to look at another feature very common in React: props. In React, you can pass props, or properties, to child components. Say you have an App
component which renders a child component called Welcome
which is a stateless functional component. You can pass Welcome
a user
property by writing:
<App>
<Welcome user='Mark' />
</App>
You use custom HTML attributes created by you and supported by React to be passed to the component. In this case, the created property user
is passed to the component Welcome
. Since Welcome
is a stateless functional component, it has access to this value like so:
const Welcome = (props) => <h1>Hello, {props.user}!</h1>
It is standard to call this value props
and when dealing with stateless functional components, you basically consider it as an argument to a function which returns JSX. You can access the value of the argument in the function body. With class components, you will see this is a little different.
There are Calendar
and CurrentDate
components in the code editor. When rendering CurrentDate
from the Calendar
component, pass in a property of date
assigned to the current date from JavaScript's Date
object. Then access this prop
in the CurrentDate
component, showing its value within the p
tags. Note that for prop
values to be evaluated as JavaScript, they must be enclosed in curly brackets, for instance date={Date()}
.
const CurrentDate = (props) => {
return (
<div>
{ /* Change code below this line */ }
<p>The current date is: </p>
{ /* Change code above this line */ }
</div>
);
};
class Calendar extends React.Component {
constructor(props) {
super(props);
}
render() {
return (
<div>
<h3>What date is it?</h3>
{ /* Change code below this line */ }
<CurrentDate />
{ /* Change code above this line */ }
</div>
);
}
};
My Solution:
const CurrentDate = (props) => {
return (
<div>
{ /* Change code below this line */ }
<p>The current date is: {props.date}</p>
{ /* Change code above this line */ }
</div>
);
};
class Calendar extends React.Component {
constructor(props) {
super(props);
}
render() {
return (
<div>
<h3>What date is it?</h3>
{ /* Change code below this line */ }
<CurrentDate date={Date()} />
{ /* Change code above this line */ }
</div>
);
}
};
Tests:
- The
Calendar
component should return a singlediv
element. - The second child of the
Calendar
component should be theCurrentDate
component. - The
CurrentDate
component should have a prop calleddate
. - The
date
prop of theCurrentDate
should contain a string of text. - The
date
prop should be generated by callingDate()
. - The
CurrentDate
component should render the value from thedate
prop in thep
tag.