Error with if elseif statements

My program is set up to ask the user for an input variable, as follows:

GOAL=input('WHAT IS YOUR GOAL?(FIT=FITNESS, FB=FAT BURN, N=NEITHER): ','s');

Then, I wrote an if, elseif statement written as:

if GOAL==('FIT')

I wrote the same thing for if GOAL==('FB') and if GOAL==('N'), and each is followed by functions to be executed for whichever the user chooses.

The error message that I am getting says:

Error using == Matrix dimensions must agree.

Am I approaching it wrong? Anything helps, thanks.

[Vaibhav Sharma]

I get the exact message for a different function of question answering

Answer 1

[bio lim]

I suggest you to use strcmp

GOAL=input('WHAT IS YOUR GOAL?(FIT=FITNESS, FB=FAT BURN, N=NEITHER):\n ','s');
if strcmp(GOAL, 'FITNESS')
    sprintf('GOOD')
elseif strcmp(GOAL, 'FB')
    sprintf('ALSO GOOD')
else strcmp(GOAL, 'N')
    sprintf('WHAT YOU SEEK HUMAN')
end

[Bree]

Thank you!!!

[Vaibhav Sharma]

I too am forced to thank you for making me aware of that function

Answer 2

[Daniel kiracofe]

In matlab, strings are arrays of characters. Two strings with different lengths have different array dimensions. e.g.

'dog' is a 3x1 character array.

'bird' is a 4x1 character array

So something like this

if ('dog' == 'bird')

will give an error because you are trying to compare a 3x1 array with a 4x1 array, and to compare arrays they must have the same length.

try the strcmp() function instead. i.e

if strcmp(GOAL, 'fit')

[Bree]

You guys are so smart, thanks!

[Vaibhav Sharma]

Really True