Is it better to have one setter method or multiple for objects with a fixed number of fields?

Question

I have a class with a member variable of type object. This object has a fixed number of fields. I'm trying to decide if I should use one setter function or multiple to mutate these fields.

To make the question more concrete, I've written the following class to model a simple organizational management structure in two different ways:

1. Multiple Setter Functions

   class Management {
       constructor() {
           this.numberOfManagers = 100;
           this.salaryDetails = {
               regionalManagerSalary: 80000,
               stateManagerSalary: 110000,
               executiveManagerSalary: 200000
           };
       }
   
       setRegionalManagerSalary(salary) {
           this.salaryDetails.regionalManagerSalary = salary;
       }
   
       setStateManagerSalary(salary) {
           this.salaryDetails.stateManagerSalary = salary;
       }  
   
       setExecutiveManagerSalary(salary) {
           this.salaryDetails.executiveManagerSalary = salary;
       }
   }
   
   const management = new Management();
   management.setRegionalManagerSalary(100000);
   management.setStateManagerSalary(120000);
   management.setExecutiveManagerSalary(210000);
   

2. One Setter Function

   class Management {
       constructor() {
           this.numberOfManagers = 100;
           this.salaryDetails = {
               regionalManagerSalary: 80000,
               stateManagerSalary: 110000,
               executiveManagerSalary: 200000
           };
       }
   
       setManagerSalary(typeOfManagerSalary, salary) {
           this.salaryDetails[typeOfManagerSalary] = salary;
       }
   }
   
   const management = new Management();
   management.setManagerSalary('regionalManagerSalary', 100000);
   management.setManagerSalary('stateManagerSalary', 120000);
   management.setManagerSalary('executiveManagerSalary', 210000);
   

Would implementation 1. be better or would implementation 2. be better?

Answer 1

I will always consider the higher readability approach if it doesn't trade off a lot of writability. The second one is more generic but the first one is more clear.

So I think the first one is better as it is more clear that there are only 3 fields in salaryDetails. Just consider you are not the author and when you see the second one, you have no idea how many fields there will be in salaryDetails as someone could just call management.setManagerSalary('someNewSalary', 100000); somewhere to add some new fields.

Unless you have more than one Management objects and each of them might have some specific fields under salaryDetails, I don't think the second approach is better.