在 JavaScript 数组中定位 'rows' 时出现问题

Question

我发现 JS 数组令人抓狂，我试图在 (JS) 二维数组中找到传递项目的 'row'。我不会在其他语言中遇到这些问题。我尝试了两种完全不同的方法，但都没有提供正确的结果。这就是我创建二维数组的方式，它似乎可以正常工作：

var _rooms = [];

var _User = function(roomNo, name) {
  this.roomNumber = roomNo;
  this.LeaderName = name;
};

_rooms.push( new _User(1, "katy") );
_rooms.push( new _User(23, "Sara") );

这是第一次尝试定位已通过的第 # 行 'name':

function findPosition(str) {
var _locater, _sought, _seeks;  
  
 for (_locater = 0; _locater < _rooms.length; _locater++) {
 _seeks = _rooms[_locater];
 _sought = _seeks.indexOf(str);     
   if (_sought >= 0) {
     return "row: " + _locater + ", col: " + _sought;
   }
 }
}

console.log(findPosition('Sara'));
//SOURCE:  "

这会抛出一个类型错误，类似于“_seeks.indexOf(str) 不是一个函数”。这是另一个尝试：

function indexOf2dArray(itemtofind) {
var _sought
  
_sought = [].concat.apply([], ([].concat.apply([], _rooms))).indexOf(itemtofind);
            
// return "false" if the item is not found
if (_sought === -1) { return false; }

// Use any row to get the rows' array length
// Note, this assumes the rows are arrays of the same length
numColumns = _rooms[0].length;

// row = the index in the 1d array divided by the row length (number of columns)
row = parseInt(_sought / numColumns);

// col = index modulus the number of columns
col = _sought % numColumns;

return [row, col]; 
}

console.log("Sara is located: " + indexOf2dArray("Sara"))  
console.log("katy is located: " + indexOf2dArray("katy")) 
//SOURCE:  https://lage.us/Javascript-Item-in-2d-Array-Using-indexOf.html

对于每个 console.log 语句，此方法的结果都是“假”。任何人都可以建议一种可靠的方法来定位 'row' 搜索到的项目出现在 JavaScript 二维数组中......？非常感谢任何建议。

Answer 1

如果您熟悉我认为可以定义的其他语言 class 为什么不使用 JavaScript classes.

创建一个 User class 和一个 Users class，其中有一个数组，您可以将每个用户 object 添加到其中。

Users 可以有一个方法来定位您将其名称传递给它的用户的索引。

class Users {

  // Add the array of users
  constructor(users) {
    this.users = users;
  }

  // Use `findIndex` to return the index
  // of the array given the `name` argument
  findPosition(name) {
    const index = this.users.findIndex(obj => {
      return obj.name === name;
    });
    return `${name} is on row ${index}`;
  }

};

class User {

  // Destructure the id and name from the user object
  constructor({ id, name }) {
    this.id = id;
    this.name = name;
  }
}

// `Users` accepts an array of user objects
const users = new Users([
  new User({ id: 1, name: 'Katy' }),
  new User({ id: 9, name: 'Boris' }),
  new User({ id: 23, name: 'Sara' })
]);

// And now you can call the users method
// to find the index of the user in the array
console.log(users.findPosition('Boris'));
console.log(users.findPosition('Sara'));
console.log(users.findPosition('Katy'));

其他文档

Answer 2

保留大部分原始代码，您可以这样做：

var _rooms = [];

var _User = function (roomNo, name) {
  this.roomNumber = roomNo;
  this.LeaderName = name;
};

_rooms.push(new _User(1, 'katy'));
_rooms.push(new _User(23, 'Sara'));

function findPosition(str) {
  var _locater, _sought, _seeks;

  for (_locater = 0; _locater < _rooms.length; _locater++) {
    _seeks = _rooms[_locater]; // _seeks is a _User
    _sought = _seeks.LeaderName.indexOf(str);

    if (_sought >= 0) {
      return 'row: ' + _locater + ', col: ' + _seeks.roomNumber;
    }
  }
}

console.log(findPosition('Sara')); // prints "row: 1, col: 23"
console.log(findPosition('kat'));  // prints "row: 0, col: 1"
console.log(findPosition('Joe'));  // prints "undefined"

另一种方法可能是使用更“现代”的 JavaScript:

function findPosition2(str) {
  const roomIndex = _rooms.findIndex((user) => user.LeaderName.includes(str));

  if (roomIndex >= 0) {
    return `row: ${roomIndex}, col: ${_rooms[roomIndex].roomNumber}`;
  } else {
    return 'not found';
  }
}

console.log(findPosition2('Sara')); // prints "row: 1, col: 23"
console.log(findPosition2('kat'));  // prints "row: 0, col: 1"
console.log(findPosition2('Joe'));  // prints "not found"

在 JavaScript 数组中定位 'rows' 时出现问题

Problems locating 'rows' within JavaScript arrays

javascript

arrays

position

row