系统学习Objective-C<基础>

#import <Foundation/Foundation.h>
BOOL areInstDifferent(int thing1, int thing2);
NSString *boolString(BOOL yesNO);
BOOL areInstDifferent(int thing1, int thing2)
{
if(thing1 == thing2)
{
return (NO);
}
else
{
return (YES);
}
}

NSString *boolString(BOOL yesNO)
{
if(yesNO == NO)
{
return (@"NO");
}
else
{
return (@"YES");
}
}

int main(int argc, const char * argv[])
{
@autoreleasepool
{
BOOL areTheyDifferent;
areTheyDifferent = areIntsDifferent(5, 5);
NSLog(@"are %d and %d different? %@", 5, 5, boolString(areTheyDifferent));
areTheyDifferent = areIntsDifferent(23, 42);
NSLog(@"are %d and %d different? %@", 23, 42, boolString(areTheyDifferent));
}
return 0;
}

以上简单的代码就是对Objective-C的很好的解释，跟C语言区别不是很大，但也有不同，值得注意的就是：#import <Foundation/Foundation.h>、NSLog(@"");、BOOL的使用,要特别注意以上三个与C语言中的区别，不要掉进BOOL的陷阱中。