Javascript operation text box readOnly

This morning I got a question about the readOnly attribute of the text box,

Specifically: use JavaScript to modify this attribute.

At the beginning, I couldn't get the value of this attribute in Javascript, so I couldn't find it on the Internet. if I did not take a closer look, I felt that I had nothing to do with what they wrote. I don't believe it, but I still cannot help it? But it cannot be :(

Finally, I carefully read one on the Internet and found that it was a problem. I didn't write it in upper case and it was all lowercase letters.

Readonly <====> readOnly

After it is changed to the latter, it is really good :)

It seems that experience is not good. The most important thing is that you have to study seriously. Your attitude determines whether you can learn something ....