D3.js aka Data-Driven Documents is a data visualization platform that has a set of tools for processing data-based documents. It is an app based on JavaScript, created by Mike Bostock, and popular for making data visualizations on the internet. The D3.js library enables the users to handle the elements of a webpage under the scope of data. These elements can be in the form of HTML, SVG, Canvas or can be created, modified and removed that depends on the data content. Now, let's come to its features such as DOM manipulation, Voronoi Diagrams, Maps, and topo, Built in-element inspector and many more. These features amaze the users to use D3.js over other similar libraries. Besides these, it has enthralling benefits such as rich toolset, large community, versatility, etc. that makes it popular among companies as well as in developers.
Well, we can’t explain all about D3.js in an introduction, so scroll down to read the full article. You will also find the online interview questions on it that will help you to crack any interviews. So, start it now and get equipped yourself with the latest D3.JS interview questions.
Below are few major features of D3.js
Q1. What is D3.js?
Expanded as Data-Driven Documents, D3.js is a javascript library. It uses Scalable Vector Graphics, HTML5, CSS (Cascading Style Sheets) to create dynamic and powerful data visualization web pages in the browser. Released in 2011, D3.js is an open-source library that gives developers full control over the final view result. With D3.js, developers can bind arbitrary data to the DOM (Data Object Model). After the binding, transformation is applied to the document to visualize the data in an interactive way. It is the popular data visualization library that is used in sites that use interactive maps, news websites, etc. D3.js is fast and also supports large datasets and dynamic behaviors.
Q2. What are applications of D3.js?
There are many applications or uses in using D3.js,
Q3. Enlist major adavantages and disadvantages of D3.js?
As a powerful visualization tool, D3.js has many advantages.
Some disadvantages of using D3.js,
Q4. Explain selections in D3?
The selection function in D3.js is used to select the DOM elements easily and apply some effects to them. It is a declarative method and operates on a set of nodes or an individual node. After selecting the elements/nodes, you can do changes like modifying its style, attributes, removing or adding an element, changing text/HTML content, etc.
D3.js provides two functions to do selections,
d3.select function selects the first matching element and d3.selectAll function selects all matching element.
//example
d3.select(‘.itemClass’).style("background-color", "blue");
The above function selects the first element with class name ‘itemClass’ and changes its background color to blue.
d3.selectAll("p").style("color", "blue");
The above function selects all the paragraphs and changes its background color to blue.
Q5. Explain transition in D3.js?
The transition function applies the given change to the selected DOM elements smoothly over a period of time instead of instantaneously. It is a key frame animation that uses predefined twinning and your own definitions. Transition supports most of the selection methods like style, attar, etc.
Example:-
d3.select ("body").transition ().style ("color", "red");
The above function selects the element of class body and changes its color to red smoothly over a period of time (the default duration is 250ms). The developers can set the duration of transition by the duration () function.
d3.select ("body").transition ().duration (700).style("color", "green");
In the above function the transition occurs for 700ms from start default frame to the end frame of green colored body.
Q6. How to format the date in d3.js?
The time format functions in D3.js is used to format the date.
To format the date in string into datetime object use the following function,
> var FormatDate = d3.timeFormat("%Y-%m-%d");
> FormatDate(“2020-01-01”).parse
Wed Jan 01 2020 00:00:00 GMT-0600 (Central Standard Time)
To get the current date in D3.js,
var formatTime = d3.timeFormat("%B %d, %Y");
formatTime(new Date); //returns “Jan 06 2020”
There are a lot of format specifiers in d3.js to format the date like %a, %b, etc for to get abbreviated weekday name, abbreviated month, etc
Q7. How to alter zoom modes in d3.js?
With the help of the d3.zoom function, we can change the zoom behavior.
d3.zoom() function creates the zoom behavior that you can apply to the selected elements
To apply the zoom behavior on selected element,
selection.call(d3.zoom.on(“zoom”, zoom));
To set zoom transform on the selected items,
selection.call(zoom.transform, d3.zoomIdentity); //it sets the identity transform for the selected items.
To translate the zoom transform for the selected item,
zoom.translateBy(selection, x, y); //it translates by the given x & y values.
To translate the zoom transform of the selected item to a given point,
zoom.translateTo(selection, x, y[, p]) //it translates the position(x, y) to the given point p.
Like these, there are many default zoom properties to change the zoom of a selected item in the d3 library.
Q8. What D3.js selects method does?
The select method in d3.js accepts a string and returns the first element that matches the string. If multiple elements match the string, then it returns the first element. If no element matches the string then it returns empty selection.
d3.select ("element") //syntax
Example:-
<html>
<head>
<body>
<div>Example for select function
<script>
// Calling the select() function
var a = d3.select("div").text();
// Getting the selected element
console.log(a); //returns “Example for select function”
</script>
</body>
</html>
</pre>Q9. What different types of slider available in d3.js?
We define different types of slider functions available in d3.js are,
d3.slider(); //creates default slider
d3.sliderLeft([scale]); //creates vertical slider. Ticks to left
d3.sliderBottom([scale]); //creates horizontal slider. Ticks to bottom
d3.sliderRight([scale]); //creates vertical slider. Ticks to right
d3.sliderTop([scale]); //creates horizontal slider. Ticks to top
d3.sliderVertical([scale]); //creates vertical slider like sliderLeft
d3.sliderHorizontal([scale]); //creates vertical slider like sliderBottom
Q10. What command used to create simple axis in d3.js?
D3.js provides the axes function to create a simple axis. An axis has simple lines, ticks, and labels.
d3.axisTop(); // Creates top horizontal axis.
d3.axisRight(); //Creates vertical right-oriented axis.
d3.axisBottom(); //Creates bottom horizontal axis.
d3.axisLeft(); //Creates left vertical axis.
| D3.js | High charts |
| It is a JavaScript library used for processing data-based documents. | It is a charting library which is written in JavaScript. |
| It applies visualization components and a data-driven approach to manipulate DOM. | It offers an easy way of adding interactive charts to web applications. |
| The available supports for the customers are tickets and Training. | Supports available in High charts are Email, tickets, and training. |
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Sharad Jaiswal
My name is Sharad Jaiswal, and I am the founder of Conax web Solutions. My tech stacks are PHP, NodeJS, Angular, React. I love to write technical articles and programming blogs.