javascript - 如何使用包含下划线的变量访问对象属性

Question

我尝试使用包含下划线的变量访问对象属性，但是，它给出错误Uncaught ReferenceError:topic_未定义。我确实调查了这个问题以寻求解决方案Dynamically access object property using variable但是没有成功。

var topics_page_no = {
    topic_1: [2,3,4],
    topic_2: [5,6,7]
}

/* Navigate to particular topic's first page based on selection */
$(document).on('click', '.topic-menu-dropdown-item', function(){
    var topic_id = $(this).data('topic-id');
    console.log(topics_page_no.topic_[topic_id][0] + ".html");
});

预期输出: 2.html/5.html

Answer 1

你可以尝试 Bracket notation 像这样:

 /* Navigate to particular topic's first page based on selection */
$(document).on('click', '.topic-menu-dropdown-item', function () {
    var topic_id = $(this).data('topic-id');
    console.log(topics_page_no["topic_" + [topic_id]][0] + ".html");
});