1

我们有一个包含数据的数组，我想users按键对其进行排序：

  • 如果users有 1 个对象，我按其name属性排序。

  • 如果users有超过 1 个条目，我按users.length.

例子：

DESCENDING: Zorya, Gorya, Dorya, Borya, Aorya, 4, 2, 0

 ASCENDING: Aorya, Borya, Dorya, Gorya, Zorya, 2, 4, 0

这是我到目前为止所做的：

const array = [{
  name: "qw",
  users: [
    { name: "Borya" },
  ],
}, {
  name: "qw",
  users: [
    { name: "Gorya" },
  ],
}, {
  name: "qw",
  users: [
   { name: "Zorya" },
 ]
}, {
  name: "qw",
  users: [
    { name: "Var" },
    { name: "Var2" },
  ],
}, {
  name: "qw",
  users: [],
}, {
  name: "qw",
  users: [
    { name: "Aorya" },
  ],
}, {
  name: "qw",
  users: [
    { name: "rwerwerwe" },
    { name: "tregdf" },
    { name: "gdfgdf" },
    { name: "Vayetrtertrr2" },
  ]
}, {
  name: "qw",
  users: [
   { name: "Dorya" },
  ],
}];

function orderCustomBy(collection, key, direction) {
  const direct = direction === "desc" ? -1 : 1;
  
  let compare = (a, b) => {
    if (a === null) return -1;
    if (b === null) return 1;
    // Just commenting this out because there's no `intlCollator` in here:
    // return intlCollator.compare(a, b);
  };
  
  if (key === "users") {
    compare = (a, b) => {
      // What should go in here?
      // intlCollator.compare(a[0].name, b[0].name);
      
      return 1;
    };
  }
  
  return [].concat(collection).sort((a, b) => {
    const result = compare(a[key], b[key]);
    return result * direct;
  });
}

console.log(orderCustomBy(array, 'users', 'asc')
  .map(item => item.users.length === 1 ? item.users[0].name : item.users.length));
  
console.log(orderCustomBy(array, 'users', 'desc')
  .map(item => item.users.length === 1 ? item.users[0].name : item.users.length));
.as-console-wrapper {
  max-height: 100% !important;
}

4

2 回答 2

1

在以下情况下，您基本上需要考虑compare函数内部的一些不同组合key === 'users：

  • 两者都有一个用户，所以我们比较user[0].name.

  • 只有a一个用户，所以a在前面b。

  • 只有b一个用户，所以b在前面a。

  • 没有一个用户，所以我们只比较users.length.

它看起来像这样：

if (a.users.length === 1 && b.users.length === 1) {
  // If both have a single user, sort by users[0].name:
  return a.users[0].name.localeCompare(b.users[0].name);
} else if (a.users.length === 1) {
  // If only `a` has a single user, `a` goes before `b`:
  return -1;
} else if (b.users.length === 1) {
  // If only `b` has a single user, `b` goes before `a`:
  return 1;
}

// Otherwise, sort by users.length:
return a.users.length - b.users.length;

在这里你可以看到它的实际效果：

const array = [{
  name: "qw",
  users: [
    { name: "Borya" },
  ],
}, {
  name: "qw",
  users: [
    { name: "Gorya" },
  ],
}, {
  name: "qw",
  users: [
   { name: "Zorya" },
 ]
}, {
  name: "qw",
  users: [
    { name: "Var" },
    { name: "Var2" },
  ],
}, {
  name: "qw",
  users: [],
}, {
  name: "qw",
  users: [
    { name: "Aorya" },
  ],
}, {
  name: "qw",
  users: [
    { name: "rwerwerwe" },
    { name: "tregdf" },
    { name: "gdfgdf" },
    { name: "Vayetrtertrr2" },
  ]
}, {
  name: "qw",
  users: [
   { name: "Dorya" },
  ],
}];

function orderCustomBy(collection, key, direction) {
  const direct = direction === "desc" ? -1 : 1;
  
  let compare;
  
  if (key === "users") {
    compare = (a, b) => {
      if (a.users.length === 1 && b.users.length === 1) {
        // If both have a single user, sort by users[0].name:
        return a.users[0].name.localeCompare(b.users[0].name);
      } else if (a.users.length === 1) {
        // If only `a` has a single user, `a` goes before `b`:
        return -1;
      } else if (b.users.length === 1) {
        // If only `b` has a single user, `b` goes before `a`:
        return 1;
      }
      
      // Otherwise, sort by users.length:
      return a.users.length - b.users.length;
    };
  } else {
    compare = (a, b) => {
      if (a === null) return -1;
      if (b === null) return 1;
      // Just commenting this out because there's no `intlCollator` in here:
      // return intlCollator.compare(a, b);
    };
  }
  
  return [].concat(collection).sort((a, b) => compare(a, b) * direct);
}

console.log(orderCustomBy(array, 'users', 'asc')
  .map(item => item.users.length === 1 ? item.users[0].name : item.users.length));
  
console.log(orderCustomBy(array, 'users', 'desc')
  .map(item => item.users.length === 1 ? item.users[0].name : item.users.length));
.as-console-wrapper {
  max-height: 100% !important;
}

于 2020-05-07T20:36:54.647 回答
0

由于这些排序标准很复杂，因此最好先将复杂数组转换为更简单的数组，以便于推理和排序。

下面的simplifyArray()函数执行此操作，生成这个未排序的数组：

[ "Borya", "Gorya", "Zorya", "2", "0", "Aorya", "4", "Dorya" ]

排序应该很简单。

function simplifyArray (arr) {
  return arr.map(el => {
    let length = el.users.length;
    if (length === 1) { return el.users[0].name; }
    else return String(length);
  });
}

const array = [
{
    name: "qw",
    users: [
      { name: "Borya" }
    ]
  },
  {
    name: "qw",
    users: [
      { name: "Gorya" }
    ]
  },
  {
    name: "qw",
    users: [
     { name: "Zorya" }
   ]
  },
  {
    name: "qw",
    users: [
      { name: "Var" },
      { name: "Var2" }
    ]
  },
  {
    name: "qw",
    users: []
  },
  {
    name: "qw",
    users: [
      { name: "Aorya" }
    ]
  },
  {
    name: "qw",
    users: [
      { name: "rwerwerwe" },
      { name: "tregdf" },
      { name: "gdfgdf" },
      { name: "Vayetrtertrr2" }
    ]
  },
  {
    name: "qw",
    users: [
     { name: "Dorya" }
    ]
  },
];

const simplerArray = simplifyArray(array);

console.log(simplerArray);

于 2020-05-07T20:31:51.040 回答