MATLAB: How to create a vector combinations in pairs

Question

How do I create a vector combinations in pairs ,with no repeated elements ,for example :

A(1,2,3,4)

1,2

1,3

1,4

2,1

2,3

2,4

3,1

3,2

3,4

4,1

4,2

4,3

I tried to use some commands like : perms And combnk , thanks in advanced

Answer 1

a=fliplr(fullfact([4 4]))
a(~diff(a')',:)=[]

or

[ii,jj]=ndgrid(1:4,1:4);
a=[jj(:) ii(:)];
a(~(a(:,1)-a(:,2)),:)=[]