Adding variables to the model

The next step in our example is to add variables to the model.

  // Create variables
  GRBVar x = model.addVar(0.0, 1.0, 0.0, GRB.BINARY, "x");
  GRBVar y = model.addVar(0.0, 1.0, 0.0, GRB.BINARY, "y");
  GRBVar z = model.addVar(0.0, 1.0, 0.0, GRB.BINARY, "z");
Variables are added through the addVar() method on a model object (or addVars() if you wish to add more than one at a time). A variable is always associated with a particular model.

The first and second arguments to the addVar() call are the variable lower and upper bounds, respectively. The third argument is the linear objective coefficient (zero here - we'll set the objective later). The fourth argument is the variable type. Our variables are all binary in this example. The final argument is the name of the variable.

The addVar() method has been overloaded to accept several different argument lists. Please refer to the Gurobi Reference Manual for further details.