Logical operators perform actions based on a boolean value, or the boolean result of a test. There are 3 logical operators:

or	Evaluates 2 boolean tests, returns True if one or both tests return True
Examples:
True or False	Returns True
True or True	Returns True
False or False	Returns False
a or b	If a or b are True, returns True. If both are False, returns false

 

and	Evaluates 2 boolean tests, returns True only if both tests return true
Examples:
True and False	Returns False
True and True	Returns True
False and False	Returns False
a and b	If a and b are both True, returns True. Otherwise returns False

 

not	Inverse operator, if the rvalue is True it returns False and vice versa
Examples:
not False	Returns True
not True	Returns False
not a	If a is True, returns False. If a is False, returns True

 

Note that the NOT operator only takes an rvalue.

Shiny supports dual syntax for logical operators. The following symbolic operators are identical to their textual counterparts, but will be more familiar to C/C++, Java, PHP and similar developers.

Operator	Equivalent to	Performs
||	or	Logical OR
&&	and	Logical AND
!	not	Logical NOT

Examples

bool Result;

int a = 1;
int b = 9;

// Result will be True, a is less than b
Result = a < b;

// Result will be True, b doesn't equal 0 but a is less than b
Result = a < b or b == 0;

// Result will be False, both conditions do not evaluate to True
Result = a < b and b == 0;

// Result will be False, a is less than b but the result is inversed
Result = not a < b;