classSet() is a neat utility for easily manipulating the DOM
class string. This previously resided inside React as a utility, but is now pulled out and library-agnostic.
Here's a common scenario
var classString = 'message';if isImportantclassString += ' message-important';if isReadclassString += ' message-read';
This can quickly get tedious, as assigning class name strings can be hard to read and error-prone.
classSet() solves this problem:
var classString =;
classSet(), pass an object with keys of the CSS class names you might or might not need. Truthy values will result in the key being a part of the resulting string.
Alternatively, you can also use it this way:
; // 'a 0 b', discards null values
No more hacky string concatenations!