# How can I change decision variable type in Concert Technologies (with Java)

I have a MILP model with continuous variables ($$y_{ij}$$) and binaries ($$x_{ij}$$). I am using Java and cplex 12.8 for implementation.

Is there a way by which - using the Java-cplex API - I would be able to write only one model that can be solved first with the binary $$x_{ij}$$'s and then for the continuous variables ($$0 \leq x_{ij} \leq 1$$)? I want to see the gap between LP-R and MIP on the fly - and don't want to build two different LP and MILP models.

IloNumVar x = cplex.numVar(0.0, 1.0);