合并javascript数组中重复的对象及其出现频率

function mergeDuplicateObjects(arr) {
  var result = {};
  
  arr.forEach(function(obj) {
    var key = JSON.stringify(obj);
    
    if (result[key]) {
      result[key].frequency++;
    } else {
      result[key] = {
        object: obj,
        frequency: 1
      };
    }
  });
  
  return Object.values(result);
}

// 示例用法
var arr = [
  { name: 'John', age: 25 },
  { name: 'Jane', age: 30 },
  { name: 'John', age: 25 },
  { name: 'Jane', age: 30 },
  { name: 'John', age: 25 }
];

var merged = mergeDuplicateObjects(arr);
console.log(merged);

[
  { object: { name: 'John', age: 25 }, frequency: 3 },
  { object: { name: 'Jane', age: 30 }, frequency: 2 }
]