寻找一个聪明的 if 条件 - Javascript

Question

我正在尝试制作一个购买物品的功能，但我不希望人们能够同时收集超过 2 件物品。

我正在寻找类似的条件。

如果 Ax + Sword = true 那么调用函数 buyItem(Dagger) 会说类似 "You cant have more than 2 items".

但考虑到我想稍后添加更多项目。

var buyItem = function (name)
{
    if (name === "Axe")
    {
        console.log("Axe");
    }
    else if (name === "Sword")
    {
        console.log("Sword");

    }
    else if (name === "Dagger")
    {
        console.log("Dagger");
    }
};

谢谢:)

Answer 1

使用一个变量来跟踪您拥有的物品数量怎么样？

int itemsHeld = 0;

获得新物品时使用itemsHeld++;，失去物品时使用itemsHeld--;

现在，当您尝试购买新商品时，只需询问 if (itemsHeld < 2) getItem();

Answer 2

商店购买计数作为私有变量

// store reference to your function returned from self invoking anonymous function enclosure (to prevent internal vairables from leaking into global scope)
var buyItem = (function(){
  // store local reference to number of items already bought
  var bought = 0;
  // return the function to be assigned to buyItem
  return function (name)
  {
    // if we reached the maximum, don't buy any more - just log a warning and return
    if(bought >= 2){
      console.log("your hands are full!!");
      return;
    } else {
      // otherwise increment the bought counter
      bought++;
    };
    if (name === "Axe")
    {
        console.log("Axe");
    }
    else if (name === "Sword")
    {
      console.log("Sword");
    }
    else if (name === "Dagger")
    {
      console.log("Dagger");
    }
  };
})();

// try it out
buyItem('Dagger');
buyItem('Sword');
buyItem('Axe');

寻找一个聪明的 if 条件 - Javascript

Looking for a smart if condition - Javascript

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if-statement

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