error while using Operands

Hi all

im trying to get this code to run but whenever i do i keep getting this error

if BSgrid(K)~=0 || BSgrid(K+1)~=0 || BSgrid(K+2)~=0 && direction==1

K=BSgrid(K)==0 && K+1==BSgrid(K+1)==0 && K+2==BSgrid(K+2)==0

elseif BSgrid(K)~=0 || BSgrid(K+10)~=0 || BSgrid(K+20)~=0 && direction==2

K=BSgrid(K)==0 && K+10==BSgrid(K+10)==0 && K+20==BSgrid(K+20)==0

end

operands to the || and && operators must be convertible to logical scalar values.

Error in battleshipfinal (line 143)

if BSgrid(K)~=0 || BSgrid(K+1)~=0 || BSgrid(K+2)~=0 && direction==1

what does it mean? and how do i get rid of it

Answer 1

[the cyclist]

Here's what is means:

true && true; % This works, and gives a scalar result

[true true] && [true false]; % This gives the error you see

The && and || operators are "short-circuit logical operators". They can be used only on scalar values -- not vectors -- because they have to be able to evaluate to simply a single true or false value, not a vector of values.

If you want a vector of logical values, you should use

[true true] & [true false]; % This works, and gives a vector result