如何编写循环遍历变量所有组合的代码

Below is part of the code of my main function

IntCon = 3;
nonlcon = @yueshu;
options = optimoptions('ga','PlotFcn', {@gaplotbestf,@gaplotstopping},'Display','diagnose',...
    'MaxStallGenerations',8,'FunctionTolerance',1e-3,'MaxGenerations',100,'PopulationSize',100);
fun = @youhua_ga1009;
lb = [0.0002 0.0002 5];
ub = [0.0003 0.0007 19];
rng default % For reproducibility
[x,fval,exitflag,output] = ga(fun,3,[],[],[],[],lb,ub,nonlcon,IntCon,options)

xlswrite([num2str(n),'output'],output_all);
end

This is part of the code of the objective function

function p_sum = youhua_ga1009(x)
%计算不同极齿尺寸和数量的耐压总和
%   此处显示详细说明
l_tooth=x(1);
h_tooth=x(2);
angle=0;
n_tooth=x(3);

step1 = 0.00001;
step2 = 0.00005;
step3 = 1;

for iii = x(1)
    x(1) = lb(1):step1:ub(1);
  for jjj = x(2)
      x(2) = lb(2):step2:ub(2);
    for kkk = x(3) 
        x(3) = lb(3):step3:ub(3);
    

I want to explore the solution under different combinations of all variables in the upper and lower limits of variables and step size conditions, but after writing the above for loop code in the objective function, the run has an error that cannot be assigned because the number of elements on the left and right is different, how to solve it