MATLAB: Convert number to string problem

homeworkMATLABmsgboxstring

I would like to ask if there is a way to output a number, which is stored as a variable, using simple commands, as shown in the following examples:

9 is converted to: 'The number is +9.'

6.54 is converted to: 'The number is +6.54.'

-7 is converted to: 'The number is -7.'

-9.2 is converted to: 'The number is -9.2.'

0 is converted to: 'The number is 0.'

I would like to display it in the command window and a message box (msgbox).

Please help. Thanks in advance.

number = 10; % an example
if number>=0
    sprintf('The number is : +%d',number)
else 
    sprintf('The number is : %d',number)
end

Assign a variable to sprintf() and then place it inside the command msgbox().

Start with "If an entry in B is greater than or equal to zero": You can either run a loop over all elements of B or use "logical indexing":

% Linear indexing:
for k = 1:numel(B)
   if B(k) >= 0
     ...
   end
end

Or two indices for rows and columns:

for r = 1:size(B, 2)
  for c = 1:size(B, 1)
    if B(r, c) >= 0
       ...
    end
  end
end

Or "logical indexing":

index = (B >= 0);
disp(B(index))

Now try to use this to modify B. Use the mentioned terms to search in the documentation and in the internet.

s='6,7,8,9,19' ;
matrix = str2num(s);