javascript - 将 Javascript 数组中的数字与数学变量相匹配

Question

请理解，我根本不是 Javascript 程序员，所以我陷入了我正在尝试构建的简单表单计算器的最后一步。我能够加载表单数组值，找到每个选项的最高值，但我希望它显示文本而不是值。

 //Set up an associative array 
 //The keys represent the cards type
 //We use this this array when the user selects a cards from the form
var cards_values = new Array();
cards_values["None"] = 0;
cards_values["Lemon"] = 5;
cards_values["Custard"] = 5;
cards_values["Fudge"] = 7;
cards_values["Mocha"] = 8;
cards_values["Raspberry"] = 10;
cards_values["Pineapple"] = 5;
cards_values["Dobash"] = 9;
cards_values["Mint"] = 5;
cards_values["Cherry"] = 5;
cards_values["Apricot"] = 8;
cards_values["Buttercream"] = 7;
cards_values["Chocolate Mousse"] = 12;



 //This function finds the cards price based on the 
 //drop down selection
function getCardValue() {
  var cardValue = 0;
  //Get a reference to the form id="cardform"
  var theForm = document.forms["cardform"];
  //Get a reference to the select id="cards"
  var selectedCard = theForm.elements["cards"];

  //set Card Price equal to value user chose
  //For example cards_values["Lemon".value] would be equal to 5
  cardValue = cards_values[selectedCard.value];

  //finally we return cardValue
  return cardValue;
}

 //This function finds the cards price based on the 
 //drop down selection
function getCardValue1() {
  var cardValue1 = 0;
  //Get a reference to the form id="cardform"
  var theForm = document.forms["cardform"];
  //Get a reference to the select id="cards"
  var selectedCard = theForm.elements["cards1"];

  //set Card Price equal to value user chose
  //For example cards_values["Lemon".value] would be equal to 5
  cardValue1 = cards_values[selectedCard.value];

  //finally we return cardValue
  return cardValue1;
}

 //This function finds the cards price based on the 
 //drop down selection
function getCardValue2() {
  var cardValue2 = 0;
  //Get a reference to the form id="cardform"
  var theForm = document.forms["cardform"];
  //Get a reference to the select id="cards"
  var selectedCard = theForm.elements["cards2"];

  //set Card Price equal to value user chose
  //For example cards_values["Lemon".value] would be equal to 5
  cardValue2 = cards_values[selectedCard.value];

  //finally we return cardValue
  return cardValue2;
}

function calculateTotal() {
  //Here we get the total price by calling our function
  //Each function returns a number so by calling them we add the values they return together
  var highcardvalue = Math.max(getCardValue(), getCardValue1(), getCardValue2());


  //display the result
  var divobj = document.getElementById('highestcard');
  divobj.style.display = 'block';
  divobj.innerHTML = "The highest card is " + highcardvalue;

}

function hideTotal() {
  var divobj = document.getElementById('highestcard');
  divobj.style.display = 'none';
}

Fiddle Demo

我不知道是否应该使用 obj 重建或者其他解决方案是否会更好。

Answer 1

您正在使用数组作为对象 - 数组采用整数键并具有长度属性。对象采用 string 键。

虽然 JavaScript 对象通常被称为关联数组，但事实并非如此。在许多方面相似，但在一些重要方面有所不同。

(数组构建在对象之上的事实意味着您正在做的事情有效，但这是不对的。)

var cards_values= {
 "None": 0,
 "Lemon": 5,
 "Custard": 7,
 "Fudge": 7
 "Mocha": 8,
 "Raspberry": 10,
 "Pineapple": 5,
 "Dobash": 9,
 "Mint": 5,
 "Cherry": 5,
 "Apricot": 8,
 "Buttercream": 7,
 "Chocolate Mousse": 12
};