Analysis of the problem of error when the post method in Ajax directly returns a number starting with 0

This article mainly introduces the analysis of the error problem of the post method in Ajax directly returning a number starting with 0. Friends in need can refer to it

Today, I found a strange error when sending a simulated verification code on the web page. question. I used the following code to preset the button to send the verification code.

This is the Node.js server

<pre style="font-family: 宋体; font-size: 9pt; background-color: rgb(255, 255, 255);"><pre name="code" class="javascript">$(".reg_code_btn").click(function(e){ 
  $(e.target).parent().children().first().val() 
  $.ajax({ 
    type:"POST", 
    url:"validate/vcode", 
    dataType:"json", 
    data:{ 
      vcode:"code" 
    }, 
    success:function(data){ 
      console.log(data); 
      alert(data); 
    }, 
    error:function(data){ 
      console.log(data); 
      alert("发生错误"); 
    } 
  }); 
});

调试结果如下：

## If we only look at our own code part, we will not find what we should questionable. But if we find during debugging that the error return values ​​​​of returning an object object have the same commonality:

Starting with 0

I will change the return value of the server If it is of JSON type, the above situation disappears.

In summary, when we use AJAX to return data, try not to return data directly. It will be safer to use JSON data.

The above is what I compiled for everyone. I hope it will be helpful to everyone in the future.

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