angular.noop is an empty function that can be used as a placeholder when you need to pass some function as a param.function foo (callback) {// Do a lot of complex thingscallback(); }// Those two have the same effect, but the later is more elegant foo(function() {}); foo(angular.noop);

A function that performs no operations. function method(callback) {var result = calculateResult();(callback || angular.noop)(result); }method(angular.noop); // no callback method(alert(result)); // alert is a callback and alerts resultUseful in situations where we do not require a callback after doing some operation.