jquery deferred 지연

 var dfd = $.Deferred(); function randomPromise(){ console.log('p', arguments); var dfd = $.Deferred(); var sec1 = Math.trunc(Math.random() * 10); setTimeout(function(){ console.log(sec1); if(sec1 % 4 == 0){ dfd.reject(sec1); }else{ dfd.resolve(sec1); } }, sec1 * 1000); return dfd.promise(); } dfd.resolve() .promise() .then(randomPromise) .then(randomPromise) .then(randomPromise) .then(randomPromise) .done(function(){ console.log('done', arguments); }) .fail(function(){ console.log('fail', arguments); }) .always(function(){ console.log('always', arguments); }) ;