我想知道為什么 foo 記錄一個(gè)值而 bar 沒(méi)有。它們?cè)谡Z(yǔ)法上似乎也相同。編輯：這是一個(gè) XY 問(wèn)題。我的目標(biāo)是獲取類的最后一個(gè)元素，foo我嘗試使用last-child. 我試過(guò)last-of-type無(wú)濟(jì)于事。const foo = document.querySelector(".some-element:last-child")const bar = document.querySelector(".foo:last-child")console.log('foo >>',foo)console.log('bar >>',bar)<article>  <div class="foo">This `div` is first.</div>  <div class="foo">This <span>nested `span` is last</span>!</div>  <div>This <em>nested `em` is first</em>, but this <em>nested `em` is last</em>!</div></article><ul>  <li class="some-element">1</li>  <li class="some-element">2</li>  <li class="some-element">3</li></ul>