Trouble converting NSNumber to int
Sorry about this silly question. I'm trying to learn objc and I'm unable to do a simple sum between 2 int values... In fact problem is bef开发者_如何学运维ore the sum.
I have an object that have an instance variable defined as a NSNumber and it's defined as a property as follows:
@interface MyObj : NSObject {
NSNumber *count;
}
@property (readwrite, assign) NSNumber *count;
@end
@implementation MyObj
@synthetize count;
@end
Then I have a class that will consume MyObj:
- (void)total:(MyObj *)mobj {
int count = [mobj.count intValue];
NSLog(@"%@", mobj.count);
NSLog(@"%@", count);
int total = 10 + count;
NSLog(@"%@", total);
}
The first NSLog prints the mobj.count nicely (let's say 5), but the second one, throws an EXC_BAD_ACCESS. And of course the program never reachs the sum.
So, what I'm doing wrong? I'm trying to convert it to a int based on this post.
TIA,
Bob
The specifier %@
is for printing Obj-C objects, and it asks for the object’s -description
. The count
in your code is an int
. Use %i
for int
s. Check out NSLog()
Specifiers.
Another possible problem:
@property (readwrite, assign) NSNumber *count;
you most likely want to use retain so it won't disappear out from under you (as a rule of thumb: use assign for primitive types, retain for objects)
@property (readwrite, retain) NSNumber *count;
NSLog(@"%@", count);
should be:
NSLog(@"%i", count);
because it's an int, not an object.
Also look at
NSLog(@"%@", total);
because its also not an object but an int
int count = [mobj.count intValue];
should be
count = [NSNumber numberWithInt:[mobj.count intValue]];
It shows there itself, count is a NSNumber, when you are trying to set it to an int.
in your NSLog try:
NSLog(@"%@", [count stringValue]);
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