按1个键对对象数组进行分组，拆分1个属性

function groupBy(arr, key) {
  return arr.reduce(function(result, obj) {
    var property = obj[key];
    if (!result[property]) {
      result[property] = [];
    }
    result[property].push(obj);
    return result;
  }, {});
}

// 示例用法
var data = [
  { name: 'Alice', age: 25, gender: 'female' },
  { name: 'Bob', age: 30, gender: 'male' },
  { name: 'Charlie', age: 35, gender: 'male' },
  { name: 'Diana', age: 28, gender: 'female' },
  { name: 'Eva', age: 32, gender: 'female' }
];

var groupedData = groupBy(data, 'gender');
console.log(groupedData);

{
  female: [
    { name: 'Alice', age: 25, gender: 'female' },
    { name: 'Diana', age: 28, gender: 'female' },
    { name: 'Eva', age: 32, gender: 'female' }
  ],
  male: [
    { name: 'Bob', age: 30, gender: 'male' },
    { name: 'Charlie', age: 35, gender: 'male' }
  ]
}