1637266380
In this Video We gonna Learn How to Download Sublime Text and Package Controller
1650870267
In the previous chapters you've learnt how to select individual elements on a web page. But there are many occasions where you need to access a child, parent or ancestor element. See the JavaScript DOM nodes chapter to understand the logical relationships between the nodes in a DOM tree.
DOM node provides several properties and methods that allow you to navigate or traverse through the tree structure of the DOM and make changes very easily. In the following section we will learn how to navigate up, down, and sideways in the DOM tree using JavaScript.
You can use the firstChild
and lastChild
properties of the DOM node to access the first and last direct child node of a node, respectively. If the node doesn't have any child element, it returns null
.
<div id="main">
<h1 id="title">My Heading</h1>
<p id="hint"><span>This is some text.</span></p>
</div>
<script>
var main = document.getElementById("main");
console.log(main.firstChild.nodeName); // Prints: #text
var hint = document.getElementById("hint");
console.log(hint.firstChild.nodeName); // Prints: SPAN
</script>
Note: The
nodeName
is a read-only property that returns the name of the current node as a string. For example, it returns the tag name for element node,#text
for text node,#comment
for comment node,#document
for document node, and so on.
If you notice the above example, the nodeName
of the first-child node of the main DIV element returns #text instead of H1. Because, whitespace such as spaces, tabs, newlines, etc. are valid characters and they form #text nodes and become a part of the DOM tree. Therefore, since the <div>
tag contains a newline before the <h1>
tag, so it will create a #text node.
To avoid the issue with firstChild
and lastChild
returning #text or #comment nodes, you could alternatively use the firstElementChild
and lastElementChild
properties to return only the first and last element node, respectively. But, it will not work in IE 9 and earlier.
<div id="main">
<h1 id="title">My Heading</h1>
<p id="hint"><span>This is some text.</span></p>
</div>
<script>
var main = document.getElementById("main");
alert(main.firstElementChild.nodeName); // Outputs: H1
main.firstElementChild.style.color = "red";
var hint = document.getElementById("hint");
alert(hint.firstElementChild.nodeName); // Outputs: SPAN
hint.firstElementChild.style.color = "blue";
</script>
Similarly, you can use the childNodes
property to access all child nodes of a given element, where the first child node is assigned index 0. Here's an example:
<div id="main">
<h1 id="title">My Heading</h1>
<p id="hint"><span>This is some text.</span></p>
</div>
<script>
var main = document.getElementById("main");
// First check that the element has child nodes
if(main.hasChildNodes()) {
var nodes = main.childNodes;
// Loop through node list and display node name
for(var i = 0; i < nodes.length; i++) {
alert(nodes[i].nodeName);
}
}
</script>
The childNodes
returns all child nodes, including non-element nodes like text and comment nodes. To get a collection of only elements, use children
property instead.
<div id="main">
<h1 id="title">My Heading</h1>
<p id="hint"><span>This is some text.</span></p>
</div>
<script>
var main = document.getElementById("main");
// First check that the element has child nodes
if(main.hasChildNodes()) {
var nodes = main.children;
// Loop through node list and display node name
for(var i = 0; i < nodes.length; i++) {
alert(nodes[i].nodeName);
}
}
</script>
1592447342
What is Pyenv?
Pyenv is a fantastic tool for installing and managing multiple Python versions. It enables a developer to quickly gain access to newer versions of Python and keeps the system clean and free of unnecessary package bloat. It also offers the ability to quickly switch from one version of Python to another, as well as specify the version of Python a given project uses and can automatically switch to that version. This tutorial covers how to install pyenv on Ubuntu 18.04.
#tutorials #apt #debian #environment #git #github #linux #package #package management #package manager #personal package archive #ppa #pyenv #python #python 3 #python support #python-pip #repository #smb #software #source install #ubuntu #ubuntu 18.04 #venv #virtualenv #web application development
1592668860
In this tutorial, we’ll read about the Android SDK Manager. We will see what is SDK manager in Android and why and how it is important for Android. So, SDK stands for Software Development Kit, which is a collection of software tools required. SDK basically helps Android to download tools and recent versions of Android. Every time a new Android version is released, along with it is released an SDK corresponding to it. This SDK must be installed by the developers for the devices.
What is SDK Manager?
A Software development kit is a set of tools required for the development of applications for Android. It also ensures that the progress of App development goes as flat as pancakes. We need SDK irrespective of the language we are using. Android SDK comes wrapped up with the Android Studio these days. An Android SDK separates the tools, platforms and other components into packages. These can be downloaded from the SDK Manager.
#android tutorials #android sdk manager #android sdk manager download #android sdk tools #android studio sdk manager #sdk download #sdk manager #sdk tools
1616572311
Originscale order management software helps to manage all your orders across channels in a single place. Originscale collects orders across multiple channels in real-time - online, offline, D2C, B2B, and more. View all your orders in one single window and process them with a simple click.
#order management system #ordering management system #order management software #free order management software #purchase order management software #best order management software
1637266380
In this Video We gonna Learn How to Download Sublime Text and Package Controller