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

Last Updated : 28 Jun, 2019

The set.empty() function in D3.js is used to return true if the given array has zero elements otherwise returns false.

Syntax:

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

Parameters: This function accepts single parameter Array which is going to be searched whether it is empty or not.

Return Value: It returns true if the given array is empty otherwise returns false.

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

Example 1:

<!DOCTYPE html> 
<html> 
  
<head> 
    <title> 
        d3.set.empty() function
    </title> 
      
    <script src = "https://d3js.org/d3.v4.min.js"></script> 
</head> 
  
<body> 
    <script> 
      
         // Initialising an array 
         Array1 = ["a"]; 
         Array2 = []; 
         Array3 = ["Geeks", "gfg", "GeeksforGeeks"]; 
            
         // Calling the d3.set.empty() function 
         A = d3.set(Array1).empty(); 
         B = d3.set(Array2).empty(); 
         C = d3.set(Array3).empty(); 
            
         // Getting the value true if the given array is  
         // empty otherwise returns false 
         console.log(A); 
         console.log(B); 
         console.log(C); 
    </script> 
</body> 
  
</html>                     

Output:

false
true
false

Example 2:

<!DOCTYPE html> 
<html> 
  
<head> 
    <title> 
        d3.set.empty() function
    </title> 
      
    <script src = "https://d3js.org/d3.v4.min.js"></script> 
</head> 
  
<body> 
    <script> 
      
        // Calling the d3.set.empty() function 
        // with a array as the parameter  
        A = d3.set([1, 2, 3, 3]).empty(); 
        B = d3.set([]).empty(); 
        C = d3.set(["a", "b", "c", "a", "b", "c"]).empty(); 
        
        // Getting the value true if the given array is 
        // empty otherwise returns false 
        console.log(A); 
        console.log(B); 
        console.log(C); 
    </script> 
</body> 
  
</html>                     