Explain the error: “constructor … cannot be applied: actual and formal differ in length”

Question

Please help me fix this error:

constructor CollegeMember in class C10h1.CollegeMember cannot be applied to given types; required: java.lang.String,java.

Answer 1

The problem is your Student constructor. It needs to chain to the CollegeMember constructor, which it should do like this:

public Student(String name, int year, String telNumber) {
    super(name, telNumber);
    this.year = year;
}

Likewise for Professor, just with rank instead of year

Note that you don't need to set name and telNumber in those constructors - that's the job of the CollegeMember constructor you're chaining to. It would also be better if you made all the fields private - then you wouldn't even be able to try to set those fields in the subclasses... which makes sense, as they're not the responsibility of the subclasses.