Example of if a variable is undefined function test() { console.log(_.isUndefined(foo)); // true, no error due to hoisting var foo = 3; console.log(_.isUndefined(foo)); // false, foo is defined now. } Example of if

var cartTemplate = ' Name: {{na}} Sku: {{sk}}'; var compiled = Handlebars.compile(cartTemplate); console.log(compiled({na: ‘Compact Round Trampoline’, sk : ‘R54’})); console.log(compiled({na: ‘Medium Round Trampoline, sk : ‘R79’})); From above sample code, we can define

Here is a good example of backbone validate Backbone.js Test by Ning Backbone.js Test by Ning

console.log(yourObject instanceof Backbone.Model); or console.log(yourObject instanceof yourModel); The instanceof operator tests whether an object has in its prototype chain the prototype property of a constructor.