javascript - cannot set property "onclick" of null

Question

As shown
The error reported is: cannot set property "onclick" of null at window.onload

Answer 1

The element cannot be obtained. Set id to input

Answer 2

1. Please post the code next time;

2. You are using document.getElementById(), but you didn’t give the id in your HTML structure;

3. It is recommended to use element.getElementsByTagName(tagName)this API, this is the tag name.