如何隐藏具有相同ID的多个div？

My HTML

<div id="a">Showcode</div>
<div id="b">Code 1</div> // b1
<div id="b">Code 2</div> // b2

My code:

$(document).ready(function(){
        $('#b').hide();
})

I am trying to hide all of the id="b" divs at once.

When I run my code I see div id = b (b1) hide but div id = b (b2) does not.

You can't use many same id

<div id="a">Showcode</div>
<div id="b">Code 1</div> // b1
<div id="c">Code 2</div> // b2

You can use class instead

<div clas="a">Showcode</div>
<div clas="a">Code 1</div> // b1
<div clas="a">Code 2</div> // b2

In Jquery

$(document).ready(function(){
        $('.a').hide();
});

HTML element IDs must be unique. Use a class name instead, which doesn't have to be unique.

$('.b').hide();

If for some reason you can't change the HTML, then you can use this, which works for duplicate IDs:

$('*[id="b"]').hide();