在Javascript上添加事件监听器

Question

I'm new to javascript and can't figure out why the following code isn't working:

 var toChange = document.getElementById("greeting"); toChange.addEventListener("mouseOver", function() { this.innerHTML = "Hi"; }); 

  <p id="greeting">Hello.</p> 

I've thoroughly researched event listeners, and I can't figure out why this code won't work. Thank you.

Answer 1

Event names are case-sensitive. Here's your code, with mouseOver replaced with mouseover .

 var toChange = document.getElementById("greeting"); toChange.addEventListener("mouseover", function() { this.innerHTML = "Hi"; }); 

  <p id="greeting">Hello.</p> 

Answer 2

请改用小写的"mouseover" 。