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freeCodeCamp/curriculum/challenges/english/03-front-end-development-libraries/react/pass-props-to-a-stateless-functional-component.md
Shaun Hamilton c2a11ad00d feat: add 'back/front end' in curriculum (#42596)
* chore: rename APIs and Microservices to include "Backend" (#42515)

* fix typo

* fix typo

* undo change

* Corrected grammar mistake

Corrected a grammar mistake by removing a comma.

* change APIs and Microservices cert title

* update title

* Change APIs and Microservices certi title

* Update translations.json

* update title

* feat(curriculum): rename apis and microservices cert

* rename folder structure

* rename certificate

* rename learn Markdown

* apis-and-microservices -> back-end-development-and-apis

* update backend meta

* update i18n langs and cypress test

Co-authored-by: Shaun Hamilton <shauhami020@gmail.com>

* fix: add development to front-end libraries (#42512)

* fix: added-the-word-Development-to-front-end-libraries

* fix/added-the-word-Development-to-front-end-libraries

* fix/added-word-development-to-front-end-libraries-in-other-related-files

* fix/added-the-word-Development-to-front-end-and-all-related-files

* fix/removed-typos-from-last-commit-in-index.md

* fix/reverted-changes-that-i-made-to-dependecies

* fix/removed xvfg

* fix/reverted changes that i made to package.json

* remove unwanted changes

* front-end-development-libraries changes

* rename backend certSlug and README

* update i18n folder names and keys

* test: add legacy path redirect tests

This uses serve.json from the client-config repo, since we currently use
that in production

* fix: create public dir before moving serve.json

* fix: add missing script

* refactor: collect redirect tests

* test: convert to cy.location for stricter tests

* rename certificate folder to 00-certificates

* change crowdin config to recognise new certificates location

* allow translations to be used

Co-authored-by: Nicholas Carrigan (he/him) <nhcarrigan@gmail.com>

* add forwards slashes to path redirects

* fix cypress path tests again

* plese cypress

* fix: test different challenge

Okay so I literally have no idea why this one particular challenge
fails in Cypress Firefox ONLY. Tom and I paired and spun a full build
instance and confirmed in Firefox the page loads and redirects as
expected. Changing to another bootstrap challenge passes Cypress firefox
locally. Absolutely boggled by this.

AAAAAAAAAAAAAAA

* fix: separate the test

Okay apparently the test does not work unless we separate it into
a different `it` statement.

>:( >:( >:( >:(

Co-authored-by: Sujal Gupta <55016909+heysujal@users.noreply.github.com>
Co-authored-by: Noor Fakhry <65724923+NoorFakhry@users.noreply.github.com>
Co-authored-by: Oliver Eyton-Williams <ojeytonwilliams@gmail.com>
Co-authored-by: Nicholas Carrigan (he/him) <nhcarrigan@gmail.com>
2021-08-13 21:57:13 -05:00

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Markdown

---
id: 5a24c314108439a4d4036169
title: Pass Props to a Stateless Functional Component
challengeType: 6
forumTopicId: 301402
dashedName: pass-props-to-a-stateless-functional-component
---
# --description--
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:
```jsx
<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:
```jsx
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.
# --instructions--
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()}`.
# --hints--
The `Calendar` component should return a single `div` element.
```js
assert(
(function () {
const mockedComponent = Enzyme.mount(React.createElement(Calendar));
return mockedComponent.children().type() === 'div';
})()
);
```
The second child of the `Calendar` component should be the `CurrentDate` component.
```js
assert(
(function () {
const mockedComponent = Enzyme.mount(React.createElement(Calendar));
return mockedComponent.children().childAt(1).name() === 'CurrentDate';
})()
);
```
The `CurrentDate` component should have a prop called `date`.
```js
assert(
(function () {
const mockedComponent = Enzyme.mount(React.createElement(Calendar));
return mockedComponent.children().childAt(1).props().date;
})()
);
```
The `date` prop of the `CurrentDate` should contain a string of text.
```js
assert(
(function () {
const mockedComponent = Enzyme.mount(React.createElement(Calendar));
const prop = mockedComponent.children().childAt(1).props().date;
return typeof prop === 'string' && prop.length > 0;
})()
);
```
The `date` prop should be generated by calling `Date()`
```js
assert(/<CurrentDatedate={Date\(\)}\/>/.test(__helpers.removeWhiteSpace(code)));
```
The `CurrentDate` component should render the value from the `date` prop in the `p` tag.
```js
let date = 'dummy date';
assert(
(function () {
const mockedComponent = Enzyme.mount(
React.createElement(CurrentDate, { date })
);
return mockedComponent.find('p').html().includes(date);
})()
);
```
# --seed--
## --after-user-code--
```jsx
ReactDOM.render(<Calendar />, document.getElementById('root'))
```
## --seed-contents--
```jsx
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>
);
}
};
```
# --solutions--
```jsx
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>
);
}
};
```