Question

In ruby, I can .inspect from an object to know the details. How can I do the similar thing in objective c? Thank you.

Answer 1

If you just want something to print you can use description as said before.

I’m not a Ruby guy myself, but if I understand this correctly .inspect in Ruby prints all the instance variables of an object. This is not something built into Cocoa. If you need this you can use the runtime system to query this information.

Here is a quick category I put together which does that:

#import <objc/objc-class.h>

@interface NSObject (InspectAsInRuby)

- (NSString *) inspect;

@end

@implementation  NSObject (InspectAsInRuby)

- (NSString *) inspect;
{
    NSMutableString *result = [NSMutableString stringWithFormat: @"<%@:%p", NSStringFromClass( [self class] ), self ];

    unsigned ivarCount = 0;
    Ivar *ivarList = class_copyIvarList( [self class], &ivarCount );

    for (unsigned i = 0; i < ivarCount; i++) {
        NSString *varName = [NSString stringWithUTF8String: ivar_getName( ivarList[i] )];
        [result appendFormat: @" %@=%@", varName, [self valueForKey: varName]];
    }

    [result appendString: @">"];

    free( ivarList );

    return result;
}

@end