Question

How do a put the contents of case 1 into a method and call it?

See code snippet below:

 Teacher jane = new Teacher("jane");
 Teacher alex = new Teacher("alex");

 Set<Teacher> teachers = new HashSet<Teacher>();
 teachers.add(jane);
 teachers.add(alex);

 int selection = scan.nextInt();
 switch (selection) {
     case 1:
         for (Teacher teacher : teachers) {
             System.out.printf("%s ", teacher.getName());
         }
         break;
 }

Answer 1

Declaration:

void printNames(Iterable<Teacher> teachers) {
    for (Teacher teacher : teachers) {
        System.out.printf("%s ", teacher.getName());
    }
}

Usage:

switch (selection) {
     case 1:
         printNames(teachers);
         break;