Scripting Documents

Selecting Doucuments Elements

Selecting Elements By ID

    var section1 = document.getElementById("section1");

Selecting Elements By type

    var spans = document.getElementsByTagName("span");

Selecting Elements by CSS class

    var warning s= document.getElementsByClassName("warning");

Selecting Elements by Name

Selecting Elements with CSS selectors

    p[lang="fr"], #log>span

The key to this API is the Document method querySelectorAll(). It takes a single string argument containing a CSS selector and returns a NodeList that represents all elements in the document that match the selector.

the document object also defines querySelector(), which is like querySelectorAll(), but returns only the first (in document order) match- ing element or null if there is no matching element. Documents As Trees of Nodes

• parentNode
• childNodes
• firstChild, lastChild
• nextSibling, previousSibling
• nodeType, Document 9, Element 1, Text 3
• nodeValue
• nodeName

Documents As Trees of Elements

• Children
• firstElementChild, lastElementChild
• nextElementSibling, previousElementSibling
• childElementCount