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> </head> <body> <script> // Initialising an array Array1 = [ "a" ]; Array2 = []; Array3 = [ "Geeks" , "gfg" , "neveropen" ]; // 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> </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> |
Output:
false true false
Ref: https://devdocs.io/d3~5/d3-collection#set_empty