Is it good that we have a method with more parameter?

Question

is it good work that design a method that have more parameter(for example five parameter) in java?

 public List<Node> loadByParentAndNeighbor(Map<String, Object> properties, String parentLabel, String neighborLabel, String parentRelation, String neighborRelation) {
     return null;
 }

It depends on what the method is doing. Why would it be bad? — Elliott Frisch, Jul 16 '14 at 06:30
Why would you want to create a method that takes 5 parameters and returns `null` ? :P — Nir Alfasi, Jul 16 '14 at 06:33
possible duplicate of [When a method has too many parameters?](http://stackoverflow.com/questions/2244860/when-a-method-has-too-many-parameters) — Nir Alfasi, Jul 16 '14 at 06:34

score 1 · Answer 1 · answered Jul 16 '14 at 06:34

1

case -1 : If the parameters are unrelated , then they cannot be put into a single container (like a list) and passed to this method. So it would be acceptable to have a method with several parameters.

case-2 : If the parameters are related.For example if an Object has 10 fields, and 5 of them are being passed to a method, then it would be cleaner and more readable to pass the object itself (rather than 5 of its parameters.)

answered Jul 16 '14 at 06:34

TheLostMind

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in this method that I post it , parentLabel and parentRelation is related , neighborLabel and neighborRelation is related. can I put them in map and method would be have three map parameter. is it good??? – user3807246 Jul 16 '14 at 06:43
@user3807246 - This is more of a design issue. You should *not* pass more than what the method needs (technically..) unless it simplifies *something* significantly. How are the fields related? – TheLostMind Jul 16 '14 at 06:47

score 0 · Answer 2 · answered Jul 16 '14 at 06:34

Too many parameters is considered bad practice and should be avoided where possible.

The reason is that if you have the following function:

public void addUser(String username, String firstname, String lastname)

It is very easy to confuse the parameters when calling the functions (was the first parameter firstname or username?).

addUser("johnd", "John", "Doe");

To solve this, it is always best to group parameters when you get too many. For instance into a class called Name with a member firstname and lastname.

Name name = new Name("John", "Doe");
addUser("johnd", name);

This problem also arises with fewer parameters (as in my example) but with more, especially when there are many of the same type, it gets gradually worse.

Is it good that we have a method with more parameter?

2 Answers2