ternary operator in matlab

Question

is there a way of typing for if like:

var = (cond) ? true : false;

or do we have to use this format?

if (cond)
 true
else
          


        

Answer 1

MATLAB doesn't have conditional expressions, but in some situations you can get a similar effect by saying, e.g., var = cond*true_expr + (1-cond)*false_expr. Unlike C's conditional expression, this will of course always evaluate both true_expr and false_expr, and if cond happens not to be either 0 or 1 (note: false behaves like 0; true behaves like 1) you'll get crazy results.

Answer 2

If you only need true or false, you can do what MatlabSorter suggests. In case you want a real tertiary operator (i.e. a = b ? c : d), there is none in MATLAB. However, using the file supplied here, you can get close.

Answer 3

MatLab doesn't have a ternary operator, or any other syntactic sugar for one-line if-statements. But if your if-statement is really simple, you could just write it in one line anyway:

if (cond); casetrue(); else; casefalse(); end

It's not as simple as ternary operator, but still better than writing it in 5 lines of code.

Answer 4

@Leonid Beschastny is correct about the inlining the if-else-end statement, but If one must, then with any assignment value that can be evaluated as boolean, one can the shortcut boolean operators || and &&:

(cond) && ((var=true_val)||1) || (var=false_val);

Rules:

1. shortcut boolean ops || and && must be used, NOT | or &
2. will work with boolean, numeric and char assignments
3. will NOT work with cell array or function handles
4. the assignments must be wrapped in parenthesis.
5. (var=true_val) must be followed by ||1 in case true_val == false
6. true and false assignments may be to different variables (i.e. (var1=true_val) while (var2=false_val))
7. true_val and false_val can be different types provided each then can be evaluated as boolean

Alternatively one can do this:

cond && (func1(..)||1) || func2(...);

provided func1 and func2 return a boolean testable value including nothing at all (but no cell arrays!):

Answer 5

Replace

c = (x ? a : b)

by

c = subsref({b; a}, substruct('{}', {x + 1}))

x should be a boolean value or 1 or 0.
true or 1 will select a
false or 0 will select b
This should work with all what cells can contain and can also be used in an intricate formular!

Answer 6

Quick and elegant. I would simply write tern( a>b, a, b) Downside is you have to copy paste everywhere, or have and extra file in the directory

function b = tern(cond, a, b)
    if cond
        b=a;
    end
end