Bootstrap component not showing properly in react project - reactjs

Question

I make a react project with yarn. I install bootstrap with yarn add bootstrap. After that I import 'bootstrap/dist/css/bootstrap.min.css' and copy paste bootstrap navbar to my code. But when started the display looks messy.
The App.js code
import logo from './logo.svg';
import './App.css';
import 'bootstrap/dist/css/bootstrap.min.css';
function App() {
return (
<div className="App">
<nav class="navbar navbar-expand-lg navbar-light bg-light">
<a class="navbar-brand" href="#">Navbar</a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarSupportedContent">
<ul class="navbar-nav mr-auto">
<li class="nav-item active">
<a class="nav-link" href="#">Home <span class="sr-only">(current)</span></a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">Link</a>
</li>
<li class="nav-item dropdown">
<a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
Dropdown
</a>
<div class="dropdown-menu" aria-labelledby="navbarDropdown">
<a class="dropdown-item" href="#">Action</a>
<a class="dropdown-item" href="#">Another action</a>
<div class="dropdown-divider"></div>
<a class="dropdown-item" href="#">Something else here</a>
</div>
</li>
<li class="nav-item">
<a class="nav-link disabled" href="#">Disabled</a>
</li>
</ul>
<form class="form-inline my-2 my-lg-0">
<input class="form-control mr-sm-2" type="search" placeholder="Search" aria-label="Search"/>
<button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button>
</form>
</div>
</nav>
</div>
);
}
export default App;
The result
Edit:
I was try with the react bootstrap instead of regular bootstrap but the result still same
My App.js
import logo from './logo.svg';
import './App.css';
import { Navbar,Nav,NavDropdown,Form,FormControl,Button} from 'react-bootstrap'
function App() {
return (
<div>
<Navbar bg="light" expand="lg">
<Navbar.Brand href="#home">React-Bootstrap</Navbar.Brand>
<Navbar.Toggle aria-controls="basic-navbar-nav" />
<Navbar.Collapse id="basic-navbar-nav">
<Nav className="mr-auto">
<Nav.Link href="#home">Home</Nav.Link>
<Nav.Link href="#link">Link</Nav.Link>
<NavDropdown title="Dropdown" id="basic-nav-dropdown">
<NavDropdown.Item href="#action/3.1">Action</NavDropdown.Item>
<NavDropdown.Item href="#action/3.2">Another action</NavDropdown.Item>
<NavDropdown.Item href="#action/3.3">Something</NavDropdown.Item>
<NavDropdown.Divider />
<NavDropdown.Item href="#action/3.4">Separated link</NavDropdown.Item>
</NavDropdown>
</Nav>
<Form inline>
<FormControl type="text" placeholder="Search" className="mr-sm-2" />
<Button variant="outline-success">Search</Button>
</Form>
</Navbar.Collapse>
</Navbar>
</div>
);
}
export default App;

Answer 1

You should be using https://react-bootstrap.github.io/getting-started/introduction instead of plain bootstrap.
It has the functionality of the components along the styles.
Would save you a lot of headaches.