Question

我是javascript的初学者，我为使用数组对象的蛇和梯子编写了一个javascript程序，但是我无法理解如何使用其开始和结束位置调用变量snake_pos。这是代码：

＆＃13;

var player_pos = 4;
var dice_value = Math.floor(Math.random() * 6) + 1;

function dice() {
  player_pos = player_pos + dice_value;
}
dice();

var last_pos = 25;

function game_rule() {
  if (player_pos >= last_pos)

  {
    alert("won the game");
  }
}

game_rule();

function snake() {
  var snake_pos = [{
      start_pos: 11,
      end_pos: 4
    },
    {
      start_pos: 20,
      end_pos: 7
    },
    {
      start_pos: 24,
      end_pos: 3
    }
  ]
}

console.log(player_pos);
console.log(dice_value);
console.log(snake_pos);

＆＃13;

Answer 1

您必须return变量snake_pos才能在函数外部使用它。之后，您可以调用array和object中的项目，看一下这个例子：

function snake(){
  // return the variable to use it outside the function
  return snake_pos = [
    {start_pos:11, end_pos:4},
    {start_pos:20, end_pos:7},
    {start_pos:24, end_pos:3}
  ]
}

//store the returned value in a variable
snake_pos = snake();

//log the first array item start_pos
console.log(snake_pos[0].start_pos);

//log the second array item start_pos
console.log(snake_pos[1].start_pos);

Answer 2

只需在您尝试访问它的同一范围内声明snake_pos：

＆＃13;

var player_pos = 4;
var dice_value = Math.floor(Math.random() * 6) + 1;

// declare it here
var snake_pos = [{
    start_pos: 11,
    end_pos: 4
  },
  {
    start_pos: 20,
    end_pos: 7
  },
  {
    start_pos: 24,
    end_pos: 3
  }
];

function dice() {
  player_pos = player_pos + dice_value;
}
dice();

var last_pos = 25;

function game_rule() {
  if (player_pos >= last_pos)

  {
    alert("won the game");
  }
}

game_rule();

function snake() {
  // It will be accessible here as well
}

console.log(player_pos);
console.log(dice_value);

// It will be accessible here
console.log(snake_pos);

＆＃13;

Answer 3

检查以下代码并尝试了解其工作原理。

// declear global variables here
         var player_pos = 4;
         var last_pos = 25;
         var dice_value = Math.floor(Math.random()*6)+1;
         // function to play dice add dice value
         function dice(){
          dice_value = Math.floor(Math.random()*6)+1;
          player_pos = player_pos + dice_value;
         }

        // we have snake positions in this, we check user on snake position or not we will do action accordingly        
        function snake(){
         var snake_pos = [
          {start_pos:11, end_pos:4},
          {start_pos:20, end_pos:7},
          {start_pos:24, end_pos:3}
          ];
          
          for(var i =0; i < snake_pos.length; i++) {
            if(snake_pos[i].start_pos == player_pos) {
              player_pos = snake_pos[i].end_pos;
            }
          }
         }
         // in this we define game rule, if user won we return true
         function game_rule(){
           if (player_pos >= last_pos)
           {
            alert("won the game");
            return true;
           } else {
            return false;
           }
         }
         // we play game until user won this game
         while(game_rule() != true) {
           console.log(player_pos);
           console.log(dice_value); 
           dice();
           snake();
         }

如果您有任何疑问，请告诉我。

快乐编码!!!

Answer 4

function Snake() {
      this.snake_pos = [{
          start_pos: 11,
          end_pos: 4
        },
        {
          start_pos: 20,
          end_pos: 7
        },
        {
          start_pos: 24,
          end_pos: 3
        }
      ]
    }
    var snake = new Snake();
    console.log(snake.snake_pos[0].start_pos);

请检查：https://www.phpied.com/3-ways-to-define-a-javascript-class/

如何在JavaScript中访问函数内的数组对象？

4 个答案: