數組對象

Question

我有一個名爲'questions'的數組，我有一個與它關聯的對象變量，它也是一個名爲'choices'的數組。

var questions = [ 
{ 
question: "What type of business do you run?", 
choices: ['Business to Business - Provide products and/or services to other 
     businesses', 'Business to Business to Consumer - Provide products 
     and/or services to other businesses for consumers', 
     'Business to Consumer - Provide products and/or services to 
     consumers'], 
choiceValues: [1, 2, 3], 
} 

我想在for循環中使用「選擇」的長度，如下所示。這句法正確嗎？我似乎無法增加「點數」變量。

function displayScore() 
{ 
var score = $('<p>',{id: 'question'}); 
var points = 0; 
for (var i = 0; i < selections.length; i++) 
{ 
    for (var j = 0; j < questions[i].choices.length; j++) 
    { 
     if (selections[i] === questions[i].choices[j]) 
     { 
      points = points + questions[i].choiceValues[j]; 
     } 
    } 
} 
score.append('You got ' + points + ' points!'); 
return score; 
} 

'選擇'的一個例子是：[0,4,0,1,0,1,0,1]。

Answer 1

的問題是，selections[i]是number(0)和questions[i].choices[j]是string('Business to Business - Provide products and/or services to other businesses')，所以，if (selections[i] === questions[i].choices[j])將無法​​正常工作（總是false）。

可以代替檢查選擇的指標：

if (selections[i] === j) 
{ 
    points = points + questions[i].choiceValues[j]; 
} 

而且，內for是沒用的，你可以這樣做：

function displayScore() 
{ 
    var score = $('<p>',{id: 'question'}); 
    var points = 0; 
    for (var i = 0; i < selections.length; i++) { 
     points += questions[i].choiceValues[selections[i]]; 
    } 
    score.append('You got ' + points + ' points!'); 
    return score; 
}