从数组中删除匹配的对象，同时将它们添加到另一个数组中

I am trying to build a 3-tiered function: First, an array lists available workshops (array is called 'workshops'). Second, another array lists workshops that a user has selected (this array is called 'selectedWorkshops'). Third, I have a final array called 'registeredWorkshops'. I am trying to build a 3-tiered function: First