Underscore.JS defaults方法

_.defaults(object, *defaults)

var _ = require('underscore');

var student = { name : 'Sam'};

// Example 1: use defaults to add class
var student1 = _.defaults(student, {class: 10});
console.log(student1);

// Example 2: use defaults to add class and school as default properties
student1 = _.defaults(student, {class: 10}, {school: 'Government'});
console.log(student1);

>node tester.js

{ name: 'Sam', class: 10 }
{ name: 'Sam', class: 10, school: 'Government' }