2D array concatenation in fortran

Question

Fortran 2003 has square bracket syntax for array concatenation, Intel fortran compiler supports it too. I wrote a simple code here for matrix concatenation:

prog         


        

Answer 1

Another way could simply be to

mat3(:,1:3) = mat1
mat3(:,4:6) = mat2

I dont know which is faster, this or the do loop above...