OR gives invalid results

Hello,

Please see the attached picture.

Its very simple but i dont get the correct results.Can anyone clarify why it outputs 12 instead of 22?

[Stephen23]

"OR gives invalid results"

Actually OR gives exactly the expected result.

"Can anyone clarify why it outputs 12 instead of 22?"

Following the rules of precedence given here:

https://www.mathworks.com/help/matlab/matlab_prog/operator-precedence.html

we can see that EQ has a higher precedence than short-circuiting ||, so your code

left == 1 || 3

is equivalent to:

(left == 1) || 3

which will always be TRUE because 3 is non-zero and so is considered TRUE.

"Its very simple but i dont get the correct results"

Yet MATLAB is just doing exactly what you told it to do. You need to pay attention to the operator precedence!

Answer 1

[Torsten]

if left == 1 || left == 3
    ...

The condition "3" is empty and thus true. MATLAB does not relate the "3" to "left".

[HARI]

oh My bad!Thank you so much!