No
cannot get property x of undefined
. Just returnsvoid 0
(undefined) if a value or a key does not exist. Highly inspired from Java's Optional Type.
yarn
yarn add mjn
npm
npm install --save mjn
cdn
<script src="https://cdn.jsdelivr.net/npm/mjn@latest/dist/dist.min.js"></script>
import maybe from "mjn"; // Or import the library as you wish using npm or CDN script tag!
const myObject = {
user: {
name: "John",
surname: "Doe",
birthday: "1995-01-29",
contacts: {
email: "[email protected]",
phone: "000 0000000"
},
languages: ["english", "italian"]
}
};
const a = maybe(myObject, "user.name");
const b = maybe(myObject, "user.languages[1]");
const c = maybe(myObject, "foo.bar.baz");
const d = maybe(myObject, "foo.bar.baz", "no value!");
const e = maybe(myObject, "foo.bar.baz", () => "I can be a function!");
console.log(a); // => John
console.log(b); // => italian
console.log(c); // => won't log anything!
console.log(d); // => "no value!"
console.log(e); // => "I can be a function!"
import React from "react";
import ReactDOM from "react-dom";
import maybe from "mjn";
const user = {
name: {
first_name: "John",
last_name: "Doe"
},
contacts: {
phone: "+00 000 0000000",
email: "[email protected]"
}
};
const App = () => (
<div className="App">
<h1>Hello {maybe(user, "name.first_name")}!</h1>
<h2> {maybe(user, "contacts.email")} </h2>
<p>
{maybe(user, "contacts.phone.office", "You don't have an office phone.")}
</p>
</div>
);
const rootElement = document.getElementById("root");
ReactDOM.render(<App />, rootElement);
Thanks goes to these wonderful people (emoji key):
Michele Riva 💻 💼 |
Paolo Roth 💻 |
Mattia Astorino 🎨 |
This project follows the all-contributors specification. Contributions of any kind welcome!