Objective C weird IF syntax - objective-c

Question

As having most of my experience in PHP, I have seen lots of new syntax rules. Most of them I have accepted and understood, but there is one that just makes no sense to me.
currentNumber = 0;
self.Label.text = [NSString stringWithFormat:#"%2.0f", result];
if ([sender tag] == 0) result = 0; {
currentOperation = (int)[sender tag];
}
As you can see, there is a bracket after result = 0;. At first I thought it was just a shortcut, just like [[something alloc]init], but when I rewrote the code like this:
currentNumber = 0;
self.Label.text = [NSString stringWithFormat:#"%2.0f", result];
if ([sender tag] == 0) result = 0;
else{
currentOperation = (int)[sender tag];
}
my app was not behaving as intended, even though the above has no syntax errors.
So my question is, what does this syntax mean? How does it translate to PHP if it even does?

Answer 1

This is not a single if statement, it is an if followed by a sequence of statements enclosed in curly braces. A better way of formatting this would be as follows:
if ([sender tag] == 0)
result = 0;
// ---- if statement ends here ----
{
currentOperation = (int)[sender tag];
}
result = 0 is the only part that is done conditionally; the rest, i.e.
currentOperation = (int)[sender tag];
is done unconditionally. In fact, the block that follows the conditional could be rewritten without curly braces; this would not change its behavior:
if ([sender tag] == 0)
result = 0;
currentOperation = (int)[sender tag];
why enclose currentOperation = (int)[sender tag]; within curly braces?
There is no point in doing that. The intention may have been to enclose both result = 0 and currentOperation = ... in the same block, but whoever wrote this code has made a typo.

Answer 2

if ([sender tag] == 0) result = 0; {
currentOperation = (int)[sender tag];
}
is equivalent to:
if ([sender tag] == 0) { result = 0; } {
currentOperation = (int)[sender tag];
}
which is equivalent to:
if ([sender tag] == 0) {
result = 0;
}
currentOperation = (int)[sender tag];
In other words, in your code only result = 0; is conditional - the rest is executed always.