D3.js interview questions

2. List the command to interpolate two objects in D3.js?

d3.interpolateObject(a,b) command is used to interpolate two objects in d3.js

3. Explain transition in D3.js?

A transition is a selection-like interface for animating changes to the DOM. Instead of applying changes instantaneously, transitions smoothly interpolate the DOM from its current state to the desired target state over a given duration.

To apply a transition, select elements, call selection.transition and then make the desired changes.

For example:

d3.select("body")
  .transition()
    .style("background-color", "red");

4. List Type of sliders are available in D3.js?

There are 7 types of slider are available in D3.js, they are

• Default slider
• Slider with start value
• Slider with slide event: 0
• Slider with default axis
• Slider with custom axis
• Slider with min, max and step values
• Vertical slider

5. Explain, what is the use of “Enter” and “Exit” selection in D3.js ?

In D3.js “Enter” selection is used to create new nodes for incoming data and “Exit” selection is used eliminate outgoing nodes that are no longer required.

6. How D3.js identify on which elements to operate?

D3.js uses CSS-style selectors to identify elements on which to operate.
Example:

d3.selectAll("p").style("color", "white");

7. Why use to D3.js?

You can use D3 js because

• D3.js lets you to build the data visualization framework
• D3.js focuses on binding data to DOM elements.
• D3.js is written in JavaScript and uses a functional style which means you can reuse code and add specific functions to your heart’s content.

8. Who developed D3.js?

Mike Bostock wrote D3.js based on his work during his Ph.D. studies at the Stanford Visualization Group. Mike worked at the The New York Times for a while and is now independently working on D3.js.

9. What does D3 stand for?

D3 stands for Data-Driven Documents

10. which is the correct way to use XML file for d3?

14. What is different between d3.scale.linear() and d3.scaleLinear().

15. How to alter zoom modes in d3 js?

16. How to set initial zoom level in D3.js?

17. How to resize an SVG when the window is resized in d3.js?

18. How to get Mouse position in D3.js?

19. What is the difference between canvas and SVG in d3.js?

20. How to format the date in d3.js?

21. List types of loops available in D3.js with syntax?

22. Explain axes in D3.js?How to create d3.js axes without numbering?

23. Explain Transition is D3.js?

24. How to calculate the area of the polygon in d3.js?

25. Define D3.js?