如何修复一个简单的js计算器(返回未定义)

function calculate(num1, num2, operator) {
  let result;

  if (operator === '+') {
    result = num1 + num2;
  } else if (operator === '-') {
    result = num1 - num2;
  } else if (operator === '*') {
    result = num1 * num2;
  } else if (operator === '/') {
    if (num2 !== 0) {
      result = num1 / num2;
    } else {
      result = 'Error: Division by zero';
    }
  } else {
    result = 'Error: Invalid operator';
  }

  return result;
}

console.log(calculate(5, 2, '+')); // Output: 7
console.log(calculate(5, 2, '-')); // Output: 3
console.log(calculate(5, 2, '*')); // Output: 10
console.log(calculate(5, 2, '/')); // Output: 2.5
console.log(calculate(5, 0, '/')); // Output: Error: Division by zero
console.log(calculate(5, 2, '%')); // Output: Error: Invalid operator