Function ngClassWatchAction

test/angular/1.4/angular.js:23215–23230

(newVal)

        }

        function ngClassWatchAction(newVal) {
          if (selector === true || scope.$index % 2 === selector) {
            var newClasses = arrayClasses(newVal || []);
            if (!oldVal) {
              addClasses(newClasses);
            } else if (!equals(newVal,oldVal)) {
              var oldClasses = arrayClasses(oldVal);
              updateClasses(oldClasses, newClasses);
            }
          }
          if (isArray(newVal)) {
            oldVal = newVal.map(function(v) { return shallowCopy(v); });
          } else {
            oldVal = shallowCopy(newVal);
          }
        }
      }
    };