throw

function getRectArea(width, height) {
  if (isNaN(width) || isNaN(height)) {
    throw new Error("!");
  }
}

try {
  getRectArea(3, "A");
} catch (e) {
  console.error(e);
  // : Error: !
}

throw expression;

throw error; // catch 
throw new Error("Required"); //  Error 

throw
new Error();

throw;
new Error();

throw (
  new Error()
);

function isNumeric(x) {
  return ["number", "bigint"].includes(typeof x);
}

function sum(...values) {
  if (!values.every(isNumeric)) {
    throw new TypeError("");
  }
  return values.reduce((a, b) => a + b);
}

console.log(sum(1, 2, 3)); // 6
try {
  sum("1", "2");
} catch (e) {
  console.error(e); // TypeError: Can only add numbers
}

readFile("foo.txt", (err, data) => {
  if (err) {
    throw err;
  }
  console.log(data);
});

function readFilePromise(path) {
  return new Promise((resolve, reject) => {
    readFile(path, (err, data) => {
      if (err) {
        reject(err);
      }
      resolve(data);
    });
  });
}

try {
  const data = await readFilePromise("foo.txt");
  console.log(data);
} catch (err) {
  console.error(err);
}