Misprint in Prog 6.10 (NOT Ex. 6.10 which doesn't exist)

[ljaygould]

One of the ways I learn from this great book is to try to type the program examples in (and often play with them to see what happens, etc.)

When doing this one, I got the strangest result: numerous (but not a consistent number) of iterations of each prime, along with a couple of wrong ones.

The reason: Count the "}"s. There's one missing (which Xcode of course put in very nicely, but in the wrong place).

There needs to be a "}" somewhere before the last if  statement, if I'm right, so that the four "{"s are properly matched...comments?

[ljaygould]

I should point out that I'm using the Kindle edition of the book; this misprint (missing "}") may not occur in print editions...

[Chris W. Rea]

I can confirm the misprint you found is also in the print 4th edition, specifically First Printing, December 2011.  Judging from the indentation, it appears the inner-most for loop is missing the close brace.

[elkie13]

Yep looks like the second for loop only executes the first if statement, not both.  So there needs to be a close brace after the first if statement.

[jimmac]

Even after reading the above explanations, I struggled with this a bit. So I though I'd post how I believe Program 6.10 should appear. (As per the book's style, only required braces are shown.)

Code: (Objective-C)

#import <Foundation/Foundation.h>

int main (int argc, const char * argv[])
{
    @autoreleasepool {
        int p, d, isPrime;
        
        for (p=2; p<=50; ++p) {
            isPrime = 1;
            
            for (d=2; d<p; ++d) {
                if (p % d == 0)
                    isPrime = 0;
            }
            if (isPrime !=0)
                NSLog(@"%i ", p);
        }
    }
    return 0;
}

[Bunchadna]

jimmac, your program looks like that's where the closed brace needs to go.  Also note, that if you simply delete the open brace that follows the second for statement, the program still works.  See my program below.

Including the brace makes the program more readable, though.