Document.head

回傳當前文件的 <head> (en-US) 元素。如果該文件有超過一個 <head> 元素，那只會回傳第一個 <head> 元素。

語法

var objRef = document.head;

範例

// in HTML: <head id="my-document-head">
var aHead = document.head;

alert(aHead.id); // "my-document-head";

alert( document.head === document.querySelector("head") ); // true

備註

document.head 是「唯讀」。若是想要將 document.head 改成別的值會失敗，這時有些瀏覽器不會告知任何錯誤訊息；有些，例如在 ECMAScript Strict 模式下 (en-US) 的 Gecko 瀏覽器，會給出 TypeError (en-US) 異常。

規範

Specification Status Comment
HTML Living Standard
The definition of 'Document.head' in that specification.		 Living Standard Initial definition.
HTML 5.1
The definition of 'Document.head' in that specification.		 Recommendation  
HTML5
The definition of 'Document.head' in that specification.		 Recommendation  

瀏覽器相容性

We're converting our compatibility data into a machine-readable JSON format. This compatibility table still uses the old format, because we haven't yet converted the data it contains. Find out how you can help! (en-US)
Feature Chrome Edge Firefox (Gecko) Internet Explorer Opera Safari
Basic support 4.0 (Yes) 4.0 (2) 9.0 11.0 5.0
Feature Android Edge Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support (Yes) (Yes) 4.0 (2) 9.0 (Yes) (Yes)

參見