Chrome中的DOM访问权限(DOM access in Chrome)

 我在玩Chrome时注意到这两个功能都是一样的： 
 
<img src="picture.jpg" id="myelement" />

function stuff(){
var x=document.getElementById("myelement");
x.style.display="none";
}//works almost everywhere

function stuff(){
myelement.style.display="none";
}//only works in Chrome
 
 为什么Chrome允许我直接从ID访问元素而不使用'getElementById'？ 这样做是不好的做法？ 这会影响性能吗？ 
 
 谢谢 

I noticed while playing around with Chrome that both of these functions work the same:
 
<img src="picture.jpg" id="myelement" />

function stuff(){
var x=document.getElementById("myelement");
x.style.display="none";
}//works almost everywhere

function stuff(){
myelement.style.display="none";
}//only works in Chrome
 
Why does Chrome allow me access the element straight from the id without using 'getElementById'? And is it bad practice to do it this way? Does it hurt performance?
 
Thanks

原文：https://stackoverflow.com/questions/10447558