Question

我有这个数组：

[{name: 'Brad', age: 30, isOlder: true, youngerBrother: 'Oleg'}, {name: 'Brad', age: 30, isOlder: false, youngerBrother: 'Michael'}]

我想检查列表中的项目是否被特定键复制。

例如

- 如果列表中的名称，年龄相同，则行重复，而不关注isOlder或者更小的兄弟。

我尝试使用lodash _uniq，但没有选项可以排除键/关注特定键

Answer 1

你可以使用它适合你的lodash _.uniqBy(arr,'key')，因为你已经在使用lodash

Answer 2

您可以使用.filter()和.some()：

var list = [
  {name: 'Brad', age: 30, isOlder: true, youngerBrother: 'Oleg'},
  {name: 'Brad', age: 30, isOlder: false, youngerBrother: 'Michael'}
];

list = list.filter(function(outer, oPos) {
  return !list.some(function(inner, iPos) {
    return iPos > oPos && inner.name == outer.name && inner.age == outer.age;
  });
});

console.log(list);

但是，直接在oPos + 1启动内部循环会更有效：

var list = [
  {name: 'Brad', age: 30, isOlder: true, youngerBrother: 'Oleg'},
  {name: 'Brad', age: 30, isOlder: false, youngerBrother: 'Michael'}
];

list = list.filter(function(outer, oPos) {
  for(var iPos = oPos + 1; iPos < list.length; iPos++) {
    if(list[iPos].name == outer.name && list[iPos].age == outer.age) {
      return false;
    }
  }
  return true;
});

console.log(list);

或者，我们可以在.filter()中迭代时构建遇到的复合键的列表。大多数浏览器应该在哈希表中实现if(keyList[key])作为查找，这使得它非常快。

var list = [
  {name: 'Brad', age: 30, isOlder: true, youngerBrother: 'Oleg'},
  {name: 'Brad', age: 30, isOlder: false, youngerBrother: 'Michael'}
];

var keyList = {};

list = list.filter(function(obj) {
  var key = obj.name + '|' + obj.age;
  
  if(keyList[key]) {
    return false;
  }
  keyList[key] = true;
  return true;
});

console.log(list);

Answer 3

请试试这个

function isDuplicate(ArrayVar) {
    var tempObj = {};
    for (var key in ArrayVar) {
        if (object.hasProperty(ArrayVar[key].name)) {
            return true;
        }
        obj[ArrayVar[key].name] = true;
    }
    return false;
}

Answer 4

以下是执行此操作的一个选项：

arr = [
    {name: 'Brad', age: 30, isOlder: true, youngerBrother: 'Oleg'}, 
    {name: 'Brad', age: 30, isOlder: false, youngerBrother: 'Michael'}
    ];

var result = checkDuplicateKeys(arr[0], arr[1], ['name', 'age']);
console.log(result);

function checkDuplicateKeys(obj1, obj2, keyList) {
    var propertyDuplicateCounter = 0;
    var result = false;

    for (var i=0; i<keyList.length; i++) {
        if (obj1.hasOwnProperty(keyList[i]) && obj2.hasOwnProperty(keyList[i])) {
            propertyDuplicateCounter += 1;
        }
    }

    if (propertyDuplicateCounter == keyList.length) {
        result = true;
    }

    return result;
}

Answer 5

您可以使用Array#some，如果name - age对于任何两个或更多对象相同，则会返回true其他false

var ar = [{name: 'Brad', age: 30, isOlder: true, youngerBrother: 'Oleg'}, {name: 'Brad', age: 30, isOlder: false, youngerBrother: 'Michael'}];

var result = ar.some(function(e) {
  if(!this[e.name + '|' + e.age]) {
    this[e.name + '|' + e.age] = true;
  } else {
    return true;
  }
}, {});

console.log(result)

Answer 6

尝试uniqBy +回调以从数组项中提取复合键：

uniqs = _.uniqBy(yourArray, x => x['name'] + x['age'])

纯粹的JS：

uniqBy = (xs, key) => {
    var keys = xs.map(key);
    return xs.filter((x, i) => keys.indexOf(key(x)) === i);
};

uniqs = uniqBy(yourArray, x => x['name'] + x['age'])

有关详细信息，请参阅https://stackoverflow.com/a/9229821/989121。

Answer 7

您可以使用Array.prototype.filter

＆＃13;

var data = [
  {name: 'Brad', age: 30, isOlder: true, youngerBrother: 'Oleg'}, 
 {name: 'Brad', age: 30, isOlder: false, youngerBrother: 'Michael'}
];

function distinctByField(arr, field) {
  var result = arr.filter(function(item) {
    var key = item[field];
    return this[key] ? false : (this[key] = true);
  }, Object.create(null));
  return result;
}

console.log(distinctByField(data, 'age'));

＆＃13;

从数组中删除重复的对象，不包括JavaScript

7 个答案: