Difference between Introduce Parameter and Change Method signature in Eclipse?

Question

Difference between Introduce Parameter and Change Method signature in Eclipse?

Answer 1

If you are speaking of the Introduce parameter Object refactoring, one answer can be found here:

http://www.refactoring.com/catalog/introduceParameterObject.html

In fact this creates a new class representing your parameters where as the Change method signature allows to change method return type, visibility and parameters.

If you are speaking about the introduce parameter when a field or local variable is selected, this will just add a new parameter to the enclosing method with the same name and the same type than the selected field or local variable and thus use this parameter instead.

Manu

Answer 2

Introduce parameter lets you convert a local expression to a parameter of the current method that will be added to the end of the parameter's list.

Change method signature allows you to introduce parameters without any special relation to your method's body, reorder or modify existing parameters.

A good overview can be found in Eclipse's help

http://help.eclipse.org/galileo/index.jsp?topic=/org.eclipse.jdt.doc.user/reference/ref-menu-refactor.htm (Galileo)

respectively

http://help.eclipse.org/helios/index.jsp?topic=/org.eclipse.jdt.doc.user/reference/ref-menu-refactor.htm (Helios)