for (let day = 1; day <= 7; day += 1) {
  if (day === 4) {
    continue;
  }

  console.log(`第 ${day} 天：完成学习打卡`);
}

let current = 1;
let sum = 0;

while (current <= 5) {
  sum += current;
  current += 1;
}

console.log("1 到 5 的总和：", sum);