访问具有空格的JSON对象键(Accessing JSON object keys having spaces [duplicate])

 我有以下json对象： 
 
{ "id": "109",
  "No. of interfaces": "4" }
 
 以下线路正常工作： 
 
alert(obj.id);
alert(obj["id"]);
 
 但是如果键有空格，那么我无法访问它们的值，例如 
 
alert(obj."No. of interfaces"); //Syntax error
alert(obj["No. of interfaces"]); //Return 'undefined'
 
 如何访问其键名称有空格的值？ 甚至有可能吗 

 
 
This question already has an answer here:
 
 
 
  
 JavaScript property access: dot notation vs. brackets?  11 answers  
 
 
 
 
I have following json object:
 
{ "id": "109",
  "No. of interfaces": "4" }
 
Following lines work fine:
 
alert(obj.id);
alert(obj["id"]);
 
But if keys have spaces then I cannot access their values e.g.
 
alert(obj."No. of interfaces"); //Syntax error
alert(obj["No. of interfaces"]); //Return 'undefined'
 
How can I access values, whose key names have spaces? Is it even possible?

原文：https://stackoverflow.com/questions/10311361