Evaluation Order in a Condition statement

[David Côme]

Hello.

Let A and B be 2 boolean expressions.
In the instruction if(A && B){/*..*/}, does the standard certify that A
will be evaluated first ?

Thanks a lot.

 

[Christopher]

Hello.

Let A and B be 2 boolean expressions.
In the instruction if(A && B){/*..*/}, does the standard certify that A
will be evaluated first ?

Thanks a lot.

left to right

 

[Paavo Helde]

Hello.

Let A and B be 2 boolean expressions.
In the instruction if(A && B){/*..*/}, does the standard certify that A
will be evaluated first ?

Even more: if A yields false, B is not evaluated at all.

 

[red floyd]

Hello.

Let A and B be 2 boolean expressions.
In the instruction if(A && B){/*..*/}, does the standard certify that A
will be evaluated first ?

I believe it depends upon whether operator&& is user-defined.
For built-in &&, yes, A is evaluated first, and B will not be evaluated
at all, if A is true.

For user defined &&, I believe the order is unspecified, and that both A
and B will be evaluated.

 

[Alexander Dong Back Kim]

left to right

This is absolutely right! Lazy evaluation!

Cheers,

 

[Erik Wikström]

This is absolutely right! Lazy evaluation!

Short circuit evaluation, lazy evaluation is something else.

 

[Victor Bazarov]

Short circuit evaluation, lazy evaluation is something else.

And actually in 'A && B' the expression 'B' is *not* evaluated at all
if 'A' yields 'false'.

V