从稍微嵌套的数组中删除重复项后，保留对象的所有键

function removeDuplicates(arr) {
  var newArr = [];
  
  for (var i = 0; i < arr.length; i++) {
    var newObj = {};
    var obj = arr[i];
    
    for (var key in obj) {
      if (!newObj.hasOwnProperty(key)) {
        newObj[key] = obj[key];
      }
    }
    
    newArr.push(newObj);
  }
  
  return newArr;
}

// 示例用法
var nestedArray = [
  { name: 'John', age: 25 },
  { name: 'Jane', age: 30 },
  { name: 'John', age: 35 },
  { name: 'Jane', age: 40 }
];

var result = removeDuplicates(nestedArray);
console.log(result);

[
  { name: 'John', age: 25 },
  { name: 'Jane', age: 30 }
]