JSFiddle - React, Tailwind, and code Playground

JavaScript

var element = [];

element['obj'] = 'one';

if ( typeof element['obj']['bg'] === 'undefined' ) {
    
    console.log('not defined');
    
    //element['obj']['bg'] = 'red';
    
    element['obj'] = {'bg':'red'};
    
    
    //console.log( element);
    
    console.log("My value:"+element['obj']['bg'] );
    
} else {
    console.log('defined');
}