Hello, here is my code

```
using JuMP, Plots, Gurobi
m=Model(with_optimizer(Gurobi.Optimizer))
@variable(m, x>=0)
@variable(m, y>=0)
k=0
obj_val=true
while k<=1
φ(x,y)=3*x+k*y
@objective(m, Max, φ(x,y))
@constraint(m, 2*x-4>=0)
@constraint(m, y-0.5*x>=0)
optimize!(m)
global k=k+0.2
global obj_val = [objective_value(m)]
end
```

I want to save the objective value of each iteration, but i don’t know how to do it.