Sort an array so that null values always come last

Question

I need to sort an array of strings, but I need it so that null is always last. For example, the array:

var arr = [a, b, null, d, null] 

When sorted ascending I need it to be sorted like [a, b, d, null, null] and when sorted descending I need it to be sorted like [d, b, a, null, null].

Is this possible? I tried the solution found below but it's not quite what I need.

How can one compare string and numeric values (respecting negative values, with null always last)?

Answer 1

Check out .sort() and do it with custom sorting. Example

function alphabetically(ascending) {      return function (a, b) {        // equal items sort equally      if (a === b) {          return 0;      }      // nulls sort after anything else      else if (a === null) {          return 1;      }      else if (b === null) {          return -1;      }      // otherwise, if we're ascending, lowest sorts first      else if (ascending) {          return a < b ? -1 : 1;      }      // if descending, highest sorts first      else {           return a < b ? 1 : -1;      }      };    }    var arr = [null, 'a', 'b', null, 'd'];    console.log(arr.sort(alphabetically(true)));  console.log(arr.sort(alphabetically(false)));