How do display array of objects in d3.js?

by scotty_walker , in category: Javascript , 3 months ago

How do display array of objects in d3.js?

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1 answer

Member

by domenico , 3 months ago

@scotty_walker 

To display an array of objects in d3.js, you can use the "selectAll" and "data" methods to bind the array to DOM elements. Here's an example code snippet:

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// Sample data array
var data = [
  { name: "John", age: 25 },
  { name: "Jane", age: 30 },
  { name: "Jim", age: 35 }
];

// Select the container element where you want to display the data
var container = d3.select("#container");

// Bind the data array to DOM elements
var elements = container
  .selectAll("div")  // Select all existing div elements inside the container
  .data(data);  // Bind the data array to the div elements

// Enter new elements appended to the container
elements.enter()
  .append("div")  // Append a new div element for each data item
  .text(function(d) { return d.name; });  // Set the text content of each div element

// Remove any extra elements not corresponding to data
elements.exit().remove();


In this example, the data array contains objects with name and age properties. We select the container element with the d3.select method, and then use the selectAll method to select all existing div elements inside the container.


We bind the data array to the selected elements using the data method. This associates each object in the data array with a corresponding DOM element.


Next, we handle three different cases: update, enter, and exit. The update case is when there are existing DOM elements that still correspond to the data. In this case, we can directly update the text content of those elements.


The enter case is when there are more data items than corresponding DOM elements. We append a new div element for each extra data item using the append method, and set its text content using a callback function.


The exit case is when there are more DOM elements than corresponding data items. We remove those extra elements using the exit method followed by remove.


Finally, the DOM is updated accordingly with the data array.