helderjbe

function sum() {
  sum.a ??= 10;
  sum.b ??= 20;

  return sum.a + sum.b;
}

console.log(sum()); // 30

sum.a = 30;

helderjbe

function sum() {
  let result = 0;
  for (const argument of arguments) {
    result += argument;
  }
  return result;
}

sum(5, 8); // 13

helderjbe

console.log(Math.ceil(0.5)); // 1

helderjbe

with (Math) {
  console.log(ceil(0.5)); // 1
}

// Out of 'with (Math) {...}', it returns an error
console.log(ceil(0.5)); // Uncaught ReferenceError: ceil is not defined

helderjbe

let a = null;
a ??= 10;
console.log(a); // "10"

let b = "something";
b ??= 10;
console.log(b); // "something"

helderjbe

const x = null;
console.log(x ?? "Hey"); // "Hey"

const y = 10;
console.log(y ?? "Something"); // 10

helderjbe

const crypto = require("crypto");

const secret = "YOUR_SECRET_KEY" // Replace this with the key from static-auth-secret

function generateTurnKey() {
  // The username is a timestamp that represents the expiration date of this credential
  // In this case, it's valid for 12 hours (change the '12' to how many hours you want)
  const username = (Date.now() / 1000 + 12 * 3600).toString();

  // Now create the corresponding credential based on the secret

helderjbe

function App() {
  const [varA, setVarA] = useState(0);

  useEffect(() => {
    if (varA > 0) return;

    const timeout = setTimeout(() => setVarA(varA + 1), 1000);

    return () => clearTimeout(timeout);
  }, [varA]); // Great, we have our dependency array correctly set

helderjbe

 function App() {
  const [varA, setVarA] = useState(0);

  useEffect(() => {
    const timeout = setTimeout(() => setVarA(varA + 1), 1000);

    return () => clearTimeout(timeout);
  }, []); // Avoid this: varA is not in the dependency array!

  return <span>Var A: {varA}</span>;

helderjbe

 function App() {
  const [varA, setVarA] = useState(0);

  useEffect(() => {
    if (varA >= 5) return;

    const timeout = setTimeout(() => setVarA(varA + 1), 1000);

    return () => clearTimeout(timeout);
  }, [varA]);