xhr is not defined
时间: 2023-08-31 12:10:17 浏览: 104
The error message "xhr is not defined" typically occurs when you try to use the XMLHttpRequest (XHR) object without first declaring it or including the necessary JavaScript library.
In modern web development, the Fetch API is commonly used instead of XHR. However, if you still want to use XHR, make sure you have the following steps in place:
1. Check if you are missing the necessary JavaScript library. Make sure you have included the appropriate script tag in your HTML file, such as:
```html
<script src="https://cdnjs.cloudflare.com/ajax/libs/xmlhttprequest/2.0.0/xmlhttprequest.min.js"></script>
```
2. Declare the XHR object before using it:
```javascript
var xhr = new XMLHttpRequest();
```
3. Ensure that you are using the correct variable name. The error message "xhr is not defined" suggests that the variable "xhr" has not been declared or assigned a value before it is being used. Double-check your code for any typos or missing variable declarations.
If you provide more specific details about your code and what you are trying to achieve, I can provide more targeted assistance.