隐式声明的javascript变量

Question

so im having an issue with some javascript and html.

in my html i have a button set up with an id

<td><button id = "accept">Accept</button></td>

and in the javascript onload function i have

acceptButton = document.getElementById("accept");

But for some reason it just started to say, variable implicitly declared , and when i try add anymore javascript, the button does not function. I am very new to javascript and really struggling to work out what this issue is due to, can someone maybe shed some light on it? thanks

I tried adding var, it takes away the error but stops the buttons functionality

Answer 1

使用var关键字声明变量：

var acceptButton = document.getElementById("accept");

Answer 2

这是因为在加载DOM之前，我已在HTML顶部加载了javascript文件