javascript - 我的 Node.js 服务器上的奇怪输出 - 删除对象

Question

我在终端中跟踪了 node.js 的输出:

Node 服务器.js

{ hand: 
   [ [ [Object], [Object] ],
     [ [Object], [Object] ],
     [ [Object], [Object] ],
     [ [Object], [Object] ] ],
  deck: 
   [ { suit: 'c', rank: 'a' },
     { suit: 'd', rank: 'a' },
     { suit: 'h', rank: 'a' },
     { suit: 's', rank: 'a' },
     { suit: 'c', rank: 'k' },
     { suit: 'd', rank: 'k' },
     { suit: 'h', rank: 'k' },
     { suit: 's', rank: 'k' },
     { suit: 'c', rank: 'q' },
     { suit: 'd', rank: 'q' },
     { suit: 'h', rank: 'q' },
     { suit: 's', rank: 'q' },
     { suit: 'c', rank: 'j' },
     { suit: 'd', rank: 'j' },
     { suit: 'h', rank: 'j' },
     { suit: 's', rank: 'j' },
     { suit: 'c', rank: '10' },
     { suit: 'd', rank: '10' },
     { suit: 'h', rank: '10' },
     { suit: 's', rank: '10' },
     { suit: 'c', rank: '9' },
     { suit: 'd', rank: '9' },
     { suit: 'h', rank: '9' },
     { suit: 's', rank: '9' },
     { suit: 'c', rank: '8' },
     { suit: 'd', rank: '8' },
     { suit: 'h', rank: '8' },
     { suit: 's', rank: '8' },
     ,
     ,
     ,
     ,
     ,
     ,
     ,
      ] }

首先，为什么我看不到手里面的Object？我正在这个对象上执行console.dir。

第二，为什么我的逗号区域是空的？我只是删除牌组[i]

这可能更像是一个 JavaScript 问题:)

js:

function deal(num_cards,num_players,deck) {
    var hand = [];
    var i = deck.length - 1;
    for (var p = num_players - 1; p >= 0; p--) {
        var player = [];
        for (var c = num_cards - 1; c >= 0; c--) {
            player.push(deck[i]);
            delete deck[i];
            i--;
        };
        hand[p] = player;
    };
    return {"hand":hand,"deck":deck};
}

Answer 1

对于第一个问题:您的deck[i]没有toString方法。定义一个可以为您提供所需信息的输出，并将替换您获得的 [object Object] 输出。例如，如果您的数组包含 Card 对象，您可以这样做:

Card.prototype.toString = function() {
    return 'suit=' + this.suit + ';rank=' + this.rank;
}

对于第二个问题:delete 确实不会删除该元素。它基本上将其设置为未定义。尝试改用deck.splice(i, 1)。