D3.js | d3.set.size() Function

Last Updated : 28 Jun, 2019

The set.size() function in D3.js is used to count the number of unique elements and return the number of unique elements in the given array.

Syntax:

d3.set([Array]).size();

Parameters: This function accepts a parameter Array of strings.

Return Value: It returns the number of unique elements from the given array.

Below programs illustrate the d3.set.size() function in D3.js:

Example 1:

<!DOCTYPE html> 
<html> 
   
<head> 
    <title>d3.set.size() Function</title> 
       
    <script src='https://d3js.org/d3.v4.min.js'></script> 
</head> 
<body> 
    
  <script> 
      
     // Initialising an array 
     Array1 = ["a", "a", "b", "c"]; 
     Array2 = ["c", "c", "c"]; 
     Array3 = ["Geeks", "gfg", "GeeksforGeeks"]; 
       
     // Calling the d3.set.size() function 
     A = d3.set(Array1).size(); 
     B = d3.set(Array2).size(); 
     C = d3.set(Array3).size(); 
       
     // Getting the number of unique values in the array 
     console.log(A); 
     console.log(B); 
     console.log(C); 
  </script> 
</body> 

Output:

3
1
3

Example 2:

<!DOCTYPE html> 
<html> 
   
<head> 
    <title>d3.set.size() Function</title> 
       
    <script src='https://d3js.org/d3.v4.min.js'></script> 
</head> 
<body> 
    
  <script> 
       
     // Calling the d3.set.size() function 
     // with a array parameter 
     A = d3.set([1, 2, 3, 3]).size(); 
     B = d3.set(["a"]).size(); 
     C = d3.set(["a", "b", "c", "a", "b", "c"]).size(); 
       
     // Getting the number of unique values in the array 
     console.log(A); 
     console.log(B); 
     console.log(C); 
  </script> 
</body> 