having two conditions for if statements

I have x= randi ([0,1],1,8, which is a 1 by 8 matrix of 0 or 1 randomly distributed and s= sum (x,2).

I wanted to write a code where

if S =1 or 2 or 3, and X(1) =0,then, Y= 100/S, elseif, S= 1 or 2 or 3, and X(1)=1, then Y=0,

But I got and error for using and/ &/ &&.

SO this is basically the code I tried using (for && on the first row, I tried 'and' and & as well).

if S == 1||2||3, && X(1) == 0,
  then Y ==100/ S;
elseif S == 1||2||3, AND X(1) ==1,
  THEN Y== 0 ;
  end

help me please!

[Stephen23]

@Christiana Won: You had the same problem in a comment to your last question:

http://www.mathworks.com/matlabcentral/answers/265921-not-logical-operators

You have again forgotten to take into account operator precedence, which was clearly explained to you in your last question.

MATLAB's relational operations are binary operators, so they can only handle two inputs at once. Read this to know more:

http://www.mathworks.com/matlabcentral/answers/262744-why-two-different-ways-of-expressing-the-same-logical-condition-lead-to-two-different-results

Answer 1

[Roger Wohlwend]

if (S == 1) || (S == 2) || (S == 3)
   if (X(1) == 0)
      Y = 100 / S;
   else
      Y = 0;
   end
end