如何在不知道键的情况下提取对象的每个值的返回类型

function getValueTypes(obj) {
  const valueTypes = {};

  for (const key in obj) {
    if (obj.hasOwnProperty(key)) {
      const value = obj[key];
      let type = typeof value;

      if (type === 'object' && value !== null) {
        if (Array.isArray(value)) {
          type = 'array';
        } else {
          type = Object.prototype.toString.call(value).slice(8, -1).toLowerCase();
        }
      }

      valueTypes[key] = type;
    }
  }

  return valueTypes;
}

// 示例对象
const obj = {
  key1: 'value1',
  key2: 123,
  key3: true,
  key4: { nestedKey: 'nestedValue' },
  key5: [1, 2, 3],
  key6: function() { console.log('Hello, world!'); }
};

// 提取每个值的返回类型
const types = getValueTypes(obj);

console.log(types);

{
  key1: 'string',
  key2: 'number',
  key3: 'boolean',
  key4: 'object',
  key5: 'array',
  key6: 'function'
}