array [4,2,7,1]创建一个返回Promise的函数。promise将计算一个数组的和，并在3秒后打印出来

function calculateSum(array) {
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      if (Array.isArray(array)) {
        const sum = array.reduce((acc, curr) => acc + curr, 0);
        resolve(sum);
      } else {
        reject(new Error('Invalid input. Expected an array.'));
      }
    }, 3000);
  });
}

const array = [4, 2, 7, 1];
calculateSum(array)
  .then(sum => {
    console.log('Sum:', sum);
  })
  .catch(error => {
    console.error('Error:', error.message);
  });