But what getElementById returns will either be an element reference, or null. Thus if the element is in the DOM, the return value will be an ... ... <看更多>

The getElementById() returns an Element object that describes the DOM element object with the specified id . It returns null if there is no element with that id ... ... <看更多>

Test suites for Web platform specs — including WHATWG, W3C, and others - wpt/Document-getElementById.html at master · web-platform-tests/wpt. ... <看更多>

document.getElementById("thepage:theform:closedcheckboxId").checked = false;. See <input type="checkbox" /> for more details on how ... ... <看更多>

Document. The object structure of PDF.js loosely follows the structure of an actual PDF. ... getElementById('the-canvas'); var context = canvas. ... <看更多>