javascript - 如何将对象添加到数组中但仅当数组的当前元素为 0 时？

Question

我有下面的代码，当两个类 (Player,Game) 都被实例化时，特定数量的玩家被插入到 Player.gameBoard 数组中。仅当数组元素为 0 时，我才尝试将 Player 类添加到数组中。因此，如果将 Player 对象插入 gameboard[0][0] 位置，则其他玩家无法覆盖他。目前，如果选择大量玩家(例如 20 人)，其中一些会被覆盖并且不会全部出现。所以我想 while 循环有问题。

var question = prompt('how many players');
var numOfPlayers = parseInt(question);

class Game {
  constructor(){
    this.health = 100;
    this.hammer = false
    this.knife = false;
    this.sword = false;
    this.baseballbat = false;
    this.damage = 0;
    this.gameBoard = [
      [0,0,0,0,0,0,0,0],
      [0,0,0,0,0,0,0,0],
      [0,0,0,0,0,0,0,0],
      [0,0,0,0,0,0,0,0],
      [0,0,0,0,0,0,0,0],
      [0,0,0,0,0,0,0,0],
      [0,0,0,0,0,0,0,0],
      [0,0,0,0,0,0,0,0],
    ];
    }
  }

class Player {
  constructor(id){
    this.id=id;
    this.location = {
      x:Math.floor(Math.random()*8),
      y:Math.floor(Math.random()*8)
    };
  }
}

var play = new Game();
let player =[];
for (i=0; i <numOfPlayers; i++ ){
    player.push(new Player(i));
    while (play.gameBoard[player[i].location.y][player[i].location.x]===0){
    play.gameBoard[player[i].location.y][player[i].location.x] = player[i];
    }
}

console.log(play);

Answer 1

与其在每个玩家创建时随机分配一个 x/y，不如创建一个包含所有可能位置的列表，并为每个新玩家随机选择一个玩家实例。你有一个 8x8 的网格。所以有 64 个可能的位置

如果对于每个玩家，您:

• 随机选择一个位置
• 删除该位置

你永远不会有重叠。

var positions = [];
for(var x=0;x<8;x++){
   for(var y=0;y<8;y++){
      positions.push({x,y});
   }
}

// pick 5 random positions for demo

for(var i=0;i<5;i++){
   var rnd = Math.floor(Math.random()*positions.length);
   console.log("random position chosen:", positions[rnd]);
   //remove this so its not picked again
   positions.splice(rnd,1);
}

应用于您的代码如下所示:

var question = prompt('how many players');
var numOfPlayers = parseInt(question);

class Game {
  constructor(){
    this.health = 100;
    this.hammer = false
    this.knife = false;
    this.sword = false;
    this.baseballbat = false;
    this.damage = 0;
    this.gameBoard = [
      [0,0,0,0,0,0,0,0],
      [0,0,0,0,0,0,0,0],
      [0,0,0,0,0,0,0,0],
      [0,0,0,0,0,0,0,0],
      [0,0,0,0,0,0,0,0],
      [0,0,0,0,0,0,0,0],
      [0,0,0,0,0,0,0,0],
      [0,0,0,0,0,0,0,0],
    ];
    }
  }

class Player {
  constructor(id, location){
    this.id=id;
    this.location = location;
  }
}

var positions = [];
for(var x=0;x<8;x++){
   for(var y=0;y<8;y++){
      positions.push({x,y});
   }
}

var play = new Game();
let player =[];
for (i=0; i <numOfPlayers; i++ ){
    var rndPos = Math.floor(Math.random()*positions.length);    
    player.push(new Player(i, positions[rndPos]));
    positions.splice(rndPos,1);
    play.gameBoard[player[i].location.y][player[i].location.x] = player[i];
}

console.log(play);

如果有意义的话，您甚至可以考虑将 availablePositions 数组作为您的 Game 的属性。