React is an easy to use JavaScript framework that lets us create front end apps.
In this article, we’ll look at how to create a height converter app with React and JavaScript.
Create the Project
We can create the React project with Create React App.
To install it, we run:
npx create-react-app height-converter
with NPM to create our React project.
Create the Height Converter App
To create the height converter app, we write:
import React, { useState } from "react";
export default function App() {
const [feet, setFeet] = useState(0);
const [inches, setInches] = useState(0);
const [centimeters, setCentimeters] = useState(0);
const submit = (e) => {
e.preventDefault();
const formValid = +feet >= 0 && +inches >= 0;
if (!formValid) {
return;
}
setCentimeters((+feet + +inches / 12) * 12 * 2.54);
};
return (
<div>
<form onSubmit={submit}>
<div>
<label>feet</label>
<input value={feet} onChange={(e) => setFeet(e.target.value)} />
</div>
<div>
<label>inches</label>
<input value={inches} onChange={(e) => setInches(e.target.value)} />
</div>
<button type="submit">calculate</button>
</form>
<p>{centimeters} cm</p>
</div>
);
}
We create the feet
, inches
and centimeters
states with the useState
hook.
Then we define the submit
function to calculate the centimeters
from feet
and inches
.
In it, we call e.preventDefault
to do client-side form submission.
Then we check if feet
and inches
are valid numbers.
If they are, then we calculate the centimeters equivalent of the feet and inches and call setCentimeters
to set the centimeter
value.
Below that, we have the form.
We pass the submit
function to the onSubmit
hook to trigger submission when we click the calculate button.
The inputs are used to set feet
and inches
.
onChange
is set to a function to set each value.
e.target.value
has the inputted value.
Below that, we display the centimeters
value.
Conclusion
We can create a height converter app easily with React and JavaScript.