Differences between childNodes. length and children. length _ javascript skills

The values of childNodes. length and children. length are often different. Because ChildNodes Not only Html Node , AllAttribute,TextAre included in ChildNodes Inside , You can use NodeType To determine the type of node, only when NodeType = 1 Make the element node, 2 Yesattribute node, 3 Is a text node. While Children. length Only count the number of nodes.
This includes calculating the node length. Pay attention to this when moving nodes.
To obtain the text of an element, for example, to obtain P Node text, which is preferred by some InnerHTML And the change is the same. In fact, this is not very good because of the use InnerHTML The browser will think that what you want to insert is a piece of label text, and you just want to insert a piece of plain text, which leads the browser to try to parse your plain text, this will cause unnecessary waste of resources. Therefore, we recommend that you use Element. firstChild. nodeValue, Why? FirstChild What about it? Because ChildNodes [0] It's a text node. You can check it if you don't believe it. NodeType .