TypeError: Cannot read property 'on' of undefined
时间: 2023-11-02 17:49:40 浏览: 47
This error message indicates that there is an attempt to access the 'on' property of an undefined object. The 'on' property is typically used for event listeners in JavaScript.
To fix this error, you should first identify the object that is undefined and ensure that it is properly defined before attempting to access its properties. This may involve checking variable assignments, function returns, or object creation.
Here are some possible causes of this error:
1. The object being referenced has not been properly initialized or instantiated.
2. The object being referenced has been deleted or removed from memory.
3. The object being referenced is not of the expected type.
4. There is a typo or other syntax error in the code that is causing the object to be undefined.
To troubleshoot the issue, you can use the console.log() method to output the value of the object at various points in your code to identify where the error is occurring. Additionally, check the documentation for the APIs or libraries you are using to ensure that you are using the correct syntax and methods.