JS limit input box code

The code is as follows: (I originally encapsulated based on the prototype, but I found that the code volume was completely increased, so I changed it back)

Thanks to sparks345 for asking questions when pasting
In this case, you can only add a few more events onpropertychange,oninput, ("value",function(id,oval,nval){})
For details, you can see here, tracking input value changes compatible processing

Source: /sohighthesky/