If statement not calling all methods returning BOOL - ios

Question

I have code like this:
-(IBAction)send {
if ([self isCorrect1] && [self isCorrect2] && ...) {
[self sendRequest];
}
}
-(BOOL)isCorrect1 {
...
}
-(BOOL)isCorrect2 {
...
}
Every isCorrect method is checking some condition showing some message in the view and returning result of the checking. I noticed that if first condition is false it will only show error message for the first method (and I need all of them to be checked) and no breakpoint is triggered inside these methods. I thought it was some kind of LLVM optimization so I created code like this:
-(IBAction)send {
BOOL correct = [self isCorrect1];
correct = correct && [self isCorrect2];
...
if (correct) {
[self sendRequest];
}
}
And is still not working correctly. Do I have to create new BOOL variable to store result for the check or is there some other way?

Answer 1

Since the first condition is evaluated to false, it won't check for the rest of the conditions and will go to the else part straightaway.
Try this.
BOOL finalResult = [self isCorrect1];
finalResult = [self isCorrect2] && finalResult;
finalResult = [self isCorrect3] && finalResult;
finalResult = [self isCorrect4] && finalResult;
...
if (finalResult) {
}
This will go through all of the isCorrect tests and will let you know if it passed all of them in the end or not.

Answer 2

The behaviour you see is the expected behaviour of the &&, namely, it "short-circuits" the evaluation, if it can determine the result in advance, before having evaluated all conditions:
expression-yielding-false && something-else
The result of the above is completely determined by the first part; regardless of what the second operand yields, the final result is false. This allows you to write something like:
if (obj != null && obj->count == 3)
{
...
}
If the && did not have the short-circuit behaviour, you'd have to write
if (obj != null)
{
if (obj->count == 3)
{
...
}
}
The || has a similar behaviour. In case of
something-yielding-true || anything
the right-hand side cannot affect the result value, as the left-hand side already returned true.
One possible work-around would be:
int succeeses = 0;
succeesses += [self isCorrect1]? 1 : 0;
succeesses += [self isCorrect2]? 1 : 0;
succeesses += [self isCorrect3]? 1 : 0;
if (successes == 3)
{
// All tests did succeed
}
else
{
// At least one failed.
}
If you need to know, which tests passed, and which failed, you can try:
BOOL passed1 = [self isCorrect1];
BOOL passed2 = [self isCorrect2];
BOOL passed3 = [self isCorrect3];
if (passed1 && passed2 && passed3)
{
// All tests did succeed
}
else
{
// At least one failed.
}
A more dense version of the above would be
int passed = 0;
passed |= [self isCorrect1]? (1 << 0) : 0;
passed |= [self isCorrect2]? (1 << 1) : 0;
passed |= [self isCorrect3]? (1 << 2) : 0;
if (passed == 7)
{
// All tests did succeed
}
else
{
if (passed & (1 << 0))
{
// First test passed
}
else
{
// First test failed
}
if (passed & (1 << 1))
{
// Second test passed
}
else
{
// Second test failed
}
if (passed & (1 << 2))
{
// Third test passed
}
else
{
// Third test failed
}
}
which is simply a more occult formulation of the version with a boolean variable per test tried.