JavaScript中元素的可见性和存在性

Question

我需要知道这是否是检查javascript中某个元素的可见性和是否存在的好习惯

if(document.getelementbyid("id") && document.getelementbyid("id").style.visibility=="visible")){}

Answer 1

Checking existence of element using document.getElementById is good practice since JavaScript will not throw an error if element does not exists on the page.

However, checking visibility is entirely dependent on the coding conditions.

Correct syntax:

if(document.getElementById("id") && document.getElementById("id").style.visibility == "visible"){}