Conditionals

Complex conditional expressions should be avoided; introduce temporary logical variables instead

By assigning logical variables to expressions, the program gets automatic documentation. The construction will be easier to read and to debug.

if (value>=lowerLimit)&(value<=upperLimit)&~ismember(value,valueArray)

    :

end

should be replaced by:

isValid = (value >= lowerLimit) & (value <= upperLimit);

isNew = ~ismember(value, valueArray);

if (isValid & isNew)

    :

end

The usual case should be put in the if part and the exception in the else part of an if/else statement

This practice improves readability by preventing exceptions from obscuring the normal path of execution.

fid = fopen(fileName);

if (fid~=-1)

    :

else

    :

end

The conditional expression if 0 should be avoided, except for temporary block commenting

Make sure that the exceptions don't obscure the normal path of execution. Using the block comment feature of the editor is preferred.

A switch statement should include the otherwise condition

Leaving the otherwise out is a common error, which can lead to unexpected results.

switch (condition)

    case ABC

        statements;

    case DEF

        statements;

    otherwise

        statements;

end

The switch variable should usually be a string

Character strings work well in this context and they are usually more meaningful than enumerated cases.