Node.js lodash defaults() apply value if a property is undefined

var _ = require('lodash');

// _.defaults applies value if a property is undefined

var shapes = [ { name: 'Square' }, 
         { name: 'Rectangle' }, 
         { name: 'Triangle', sides: 3 }, 
         { name: 'Pentagon', sides: 5 },
         { name: 'Circle', sides: NaN } ];


_.each(shapes, function(shape) {
  _.defaults(shape, { sides: 4 } );/*from w w  w .j  a  va2 s.c o  m*/
});


console.log(shapes);