const getLevel = (score) => (score >= 80 ? "达标" : "继续练习");
const add = (a, b) => a + b;

const tracks = ["DOM", "异步", "模块化"];
const labels = tracks.map((track) => `[${track}]`);

document.getElementById("output").textContent = JSON.stringify(
  {
    level: getLevel(86),
    sum: add(12, 8),
    labels,
  },
  null,
  2
);