数组对象

Question

我有一个名为'questions'的数组，我有一个与它关联的对象变量，它也是一个名为'choices'的数组。

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循环中使用“选择”的长度，如下所示。这句法正确吗？我似乎无法增加“点数”变量。

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; 
} 

'选择'的一个例子是：[0,4,0,1,0,1,0,1]。

Answer 1

的问题是，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])将无法​​正常工作（总是false）。

可以代替检查选择的指标：

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

而且，内for是没用的，你可以这样做：

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; 
}