how can i write if condition for an empty array?

Following is the code:

clc
A=[333.3333 -333.3333 0;333.3333  666.6667 -333.3333;0 -333.3333  333.3333]
F=[0;0;10]
o=[]
%B=[1,o]
n1=input('Boundry Condition for N1')
n2=input('Boundry Condition for N2')
B=[n1,n2]
if  n1==1 & n2==o;%1=fixed & o=free, but cant read this after running file
    c=2
    d=n
    disp('Loop 1')
elseif n1==o &  n2==1;
     c=1
     d=n-1
      disp('Loop 2')
else  n1==1 & n2==1;
     c=2
     d=n-1
     disp('Loop 3')
end
AuxEqn=A(B,c:d)
AuxRHs=F(B)

A(B,:)=[];
A(:,B)=[]
F(B)=[]
U=inv(A)*F
R=AuxEqn*U

Answer 1

[Walter Roberson]

You cannot compare [] to anything. Use isempty() to test for empty matrix.

[Adi]

Ok thank you.

[Adi]

I tried using isempty() but its again showing error, I cant figure out how to incorporate this in my if statement. I would highly appreciate If you can check my code. Regards

[Walter Roberson]

if  n1==1 && isempty(n2);
    c=2
    d=n
    disp('Loop 1')
elseif isempty(n1) &&  n2==1
     c=1
     d=n-1
      disp('Loop 2')
else  n1==1 && n2==1;
     c=2
     d=n-1
     disp('Loop 3')
else
     disp('Something else!')
end

[Adi]

@Walter Roberson: This has solved my Problem Thank you so much.