javascript - 如何添加一些随机性来填充此列表？

Question

我正在尝试填充测验中的答案列表。正确的答案始终是数据对象中的a0。我怎样才能使第一个答案并不总是正确的？如有提示，我们将不胜感激!

JS:

data = [
        {"q":"How much?", "a0":"20%", "a1": "1%", "a2": "10%", "a3": "5%"},
        {"q":"What", "a0":"Ball", "a1": "Stone", "a2": "Bierd", "a3": "Carl"},
        {"q":"When?", "a0":"1999", "a1": "2000", "a2": "2001", "a3": "2002"}
        ];

function addData() {

var ids =['a','b','c','d'];
for (var j=0; j < ids.length; j++) {

    //Populate answers into list
    document.getElementById(ids[j]).innerHTML = data[q]['a'+j];

    //Add class 'correct' to the li with the right answer (always a0 in the data object)
    if (j==0) {
    document.getElementById(ids[j]).setAttribute('class', 'correct');
    }
};
}

HTML:

<ul class="answers_quiz">
<li id="a"></li>
<li id="b"></li>
<li id="c"></li>
<li id="d"></li>
</ul>

Answer 1

只需使用随机数对数组进行排序:

var ids =['a','b','c','d'];
ids.sort(function(x, y) {
    return parseInt(Math.random() * ids.length);
});
for (var j=0; j < ids.length; j++) {
    //.....
}

Live test case 。 (随机排序)