Out of curiosity I ran your code against both jQuery’s .index() and my below code: function findRow3(node) { var i = 1; while (node = node.previousSibling) { if (node.nodeType === 1) { ++i } } return i; } Jump to jsperf results It turns out that jQuery is roughly 50% slower than your implementation (on … Read more
It means that document.getElementById(“lastName”) is returning undefined and you’re trying to call classList on undefined itself. In your HTML input has the attribute name which equals lastName but there is no actual id=”lastname” Either add the attribute id to your input or change getElementById to getElementsByName. Note that getElementsByName doesn’t return a single item.
In 2020: The is attribute is now part of HTML spec in the Custom Elements specification. It follows the polymer spec and is documented for developers at mdn. Only Edge still hasn’t updated to include this spec but it its new chromium-based implementation, in 2020, its availability may become widespread. In 2017: There is no … Read more
A reference to an element will never look “falsy”, so leaving off the explicit null check is safe. Javascript will treat references to some values in a boolean context as false: undefined, null, numeric zero and NaN, and empty strings. But what getElementById returns will either be an element reference, or null. Thus if the … Read more
The DOM is actually a separate thing to JavaScript. The DOM can be accessed from other languages, such as VBScript in IE. And general-purpose programming languages like Java, Python, PHP etc have their own non-browser-based DOM libraries. The basic DOM operations that work on both HTML and general XML documents can be found in DOM … Read more
document.body.innerHTML = ”; does clear the body, yeah. But it clears the innerHTML as it is at the moment the code is ran. As you run the code before the images and the script are actually in the body, it tries to clear the body, but there’s nothing to clear. If you want to clear … Read more
Try var mydiv = $(‘my-div-selector’); mydiv.find(‘.myUniqueElement’).appendTo(mydiv) or simple $(‘my-div’).append($(‘.myUniqueElement’))
Other replies have pointed out that self is not going to refer to the FORM and that self is window. They’re right; self is window. Well, except when it isn’t. In either IE6 or IE7 (forgot), self.onload would not fire, though window.onload would. All official versions of IE (and even IE9pr3) have an odd, intransitive … Read more
With IE 10 and above, you can use the DOM Parser object to parse DOM directly from HTML. var parser = new DOMParser(); var doc = parser.parseFromString(html, “text/html”); var paragraphs = doc.querySelectorAll(‘p’);
What seems to be confusing this thread is the difference between: $(‘.selector’).append(“<input type=”text”/>”); Which appends the target element as a child of the .selector. And $(“<input type=”text” />”).appendTo(‘.selector’); Which appends the target element as a child of the .selector. Note how the position of the target element & the .selector change when using the different … Read more