reference URL: http://www.w3cfuns.com/article-5593688-1-1.html Document.queryselector ("body");//Return Body nodedocument.queryselector ("#k");//returns the node with the ID kdocument.queryselector ("#k span");//Returns the first span node under a node with the ID kdocument.queryselector ("#k"). Queryselector ("span");//Returns the first span node under a node with the ID kdocument.queryselectorall ("Li");//Returns the node collection (NodeList) used by TagName as LiDocument.queryselectorall ("Div. Li");//Returns a div of class Li Summary:1. The resulting element is not required to be troublesome multiple getelementby. , try to use Getelementby., because he is faster. 2. The resulting elements need to be cumbersome to getelementby multiple times. Combination to get the words using Queryselector, convenient. 3. Look at the actual situation, you decide whether the convenience or performance first.
Introduction to using the Queryselector method
