logical operators
Logical Operators:
They are used to combine two or more conditions/constraints or to complement
the evaluation of the original condition under consideration. They are
described below:
Logical AND operator: The ‘&&’ operator returns true when both the conditions
under consideration are satisfied. Otherwise it returns false. For example, a
&& b returns true when both a and b are true (i.e. non-zero).
Logical OR operator: The ‘||’ operator returns true even if one (or both) of
the conditions under consideration is satisfied. Otherwise it returns false.
For example, a || b returns true if one of a or b or both are true
(i.e. non-zero). Of course, it returns true when both a and b are true.
Logical NOT operator: The ‘!’ operator returns true the condition in
consideration is not satisfied. Otherwise it returns false. For example,
!a returns true if a is false, i.e. when a=0.