javascript - 获取ReferenceError：外观未定义(Getting ReferenceError: appearance is not defined)

Question

I am trying to access an super hero api and for some of the data it keeps saying that the data is undefined.(我正在尝试访问超级英雄api，对于某些数据，它一直在说数据未定义。)

 var html = "";
$.each(data.results,function(i,results){
html += "<li> first appearance: " + results.biography.first-appearance +"</li>";
// it is not showing anything with a "-" in but the rest are working fine 

 })
 $("#Results").html(html);

  ask by Super_Fly translate from so

Answer 1

In the same way that object keys with hyphens in them need to be quoted, when you're accessing the key you need to use square bracket notation with quotes:(以与它们之间带有连字符的对象键相同的方式进行引用，在访问键时，需要使用带引号的方括号表示法：)

 const a = [{ biography: 'a', 'first-appearance': 'b' }]; console.log(a[0]['first-appearance'])