If abc(1==1) returns true will then call abc(2) ?
No, it won't. This behavior is known as short-circuiting. It is guaranteed by C and C++ standards.
C11(n1570), § 6.5.13 Logical AND operator
Unlike the bitwise binary & operator, the && operator guarantees left-to-right evaluation; if the second operand is evaluated, there is a sequence point between the evaluations of
the first and second operands. If the first operand compares equal to 0, the second operand is not evaluated.
(Emphasis is mine.)
The same applies to the || operator.
