Khalid mock

[Sanjeev Gupta]

Which operators will always evaluate all operands?
a) | |
b) +
c) &&
d) %
e) ?:
The correct answer given is 'b' and 'd'. According to me 'e' should also be correct. Somebody please throw some light on this.

[sona gold]

e is not correct
(a<b)?this will execute:if the condition isfalse>
if (a<b) evaluates to true then the part after ? evaluates, the second half does not evaluate>
but if the condition(a<b) is false , the true part will not execute >
so if does not opeate on everything

[nitin sharma]

sanjeev,
?: operator is not true because it's depend's on the condition if the condition is true then the statement immediately after the colon get's executed and the other(false) part is left untouched,therefore that part is not evaluated at all.
In the case of && same thind happen's if the first operand is false, the cursor does not evaluate the second operand.

[Hassan Naqvi]

Hi,
How can we say " + " , "always" operates both the operands.
Well, " + " in some cases is the unary operator too.
For example,
+8, +a.. etc
Please clear this point.
Hassan

[Ravindra Mohan]

Hi folks,
The answer is (b) and (d)explained as follows:

a)  x | | y   // wrong it is a short circuited operator, assume x and y are boolean, if x is true then y is not evaluated as the result will be true irrespective of 'y'
b) +          // true because x+y will always be performed on x and y (if the expression x and y are valid )  
c) &&        // wrong it is also a  short circuited operator, assume x and y are boolean, if x is false then y is not evaluated as the result will be false irrespective of 'x'
d) %        // true because x%y will always be evaluated even in case y=0, in that case it will throw an exception 'devide by /'  but that is a Runtime exception, but that decision was taken by the JVM ONLY after evaluating that y is indeed is zero.
e) ?:         // false because if we consider y = x ? (a+b) : (a-b); then in case  'x' is true then the expression  (a-b) will not be evaluated.   

Hope this clarifies..
Cheers,
Ravindra Mohan.

[This message has been edited by Ravindra Mohan (edited May 05, 2001).]