D3.js node.links() Function

Last Updated : 18 Sep, 2020

The node.links() function returns an array of links to the children of the node object, each link object has a source and a target field that hold references to child nodes.

Syntax:

node.links();

Parameters: This method does not accept any parameters.

Return Values: This method returns an array of links to the children of the node object.

Example 1:

HTML

<!DOCTYPE html> 
<html> 
  
<head> 
    <meta charset="utf-8"> 
  
    <script src= 
        "https://d3js.org/d3.v5.min.js"> 
    </script> 
</head> 
  
<body> 
    <script> 
        var data = { 
            "name":"GeeksforGeeks",  
            "about":"Computer Science Portal", 
            "children":[ 
                {"name":"GFG1"}, 
                {"name":"GFG2"}, 
                {"name":"GFG3"} 
            ] 
        } 
        var root = d3.hierarchy(data); 
        a=root.links(); 
        console.log(a); 
        for (i=0;i<a.length;i++){ 
            console.log(a[i].source.children) 
        } 
    </script> 
</body> 
  
</html>

Output:

Example 2: Root containing no children return empty links array.

HTML

<!DOCTYPE html> 
<html> 
  
<head> 
    <meta charset="utf-8"> 
  
    <script src= 
        "https://d3js.org/d3.v5.min.js"> 
    </script> 
</head> 
  
<body> 
    <script> 
        var data = {"name":"GFG1"} 
  
        var root = d3.hierarchy(data); 
  
        console.log(root.links()); 
    </script> 
</body> 
  
</html>