Convert variable name to string

Question

How can I convert a variable name into a string?

Example:

From this:

NSString *someVariable
int otherVariable

I want to get a NSString with the actual name of the variable, no matter what type it is.
So, for the two variables above I would want to get their names (someVariable, otherVariable).

tagyro · Accepted Answer · 2015-08-04 13:20:43Z

5

I managed to solve my problem with this code snippet:

Import the objc runtime
#import <objc/runtime.h>

and you can enumerate the properties with:

- (NSArray *)allProperties
{
    unsigned count;
    objc_property_t *properties = class_copyPropertyList([self class], &count);

    NSMutableArray *rv = [NSMutableArray array];

    unsigned i;
    for (i = 0; i < count; i++)
    {
        objc_property_t property = properties[i];
        NSString *name = [NSString stringWithUTF8String:property_getName(property)];
        [rv addObject:name];
    }

    free(properties);

    return rv;
}

Hope it helps someone.

edited Aug 4, 2015 at 13:20

answered Oct 23, 2012 at 7:38

tagyro

1,6892 gold badges21 silver badges36 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Yuji · Accepted Answer · 2012-10-08 15:36:15Z

1

Just add " ... " around the variable name. i.e.

"someVariable"
"otherVariable"

to get the string (as a const char*.) If you want an NSString*, use

@"someVariable"
@"otherVariable"

Within a macro, you can use the construction #... to put the quote ... unquote around a macro variable, e.g.

#define MyLog(var) NSLog(@"%s=%@", #var, var)

so that

MyLog(foo);

is expanded to

NSLog(@"%s=%@", "foo", foo);

answered Oct 8, 2012 at 15:36

Yuji

34.2k3 gold badges72 silver badges88 bronze badges

Comments

Tom Wetmore · Accepted Answer · 2012-10-08 15:30:09Z

0

These are C declarations, and C does not have the introspection capability to give you what you want.

You could probably write a preprocessor macro that would both declare a variable and also declare and initialize a second variable with the name of the first.

But this begs the question of why you need this level of introspection at all.

answered Oct 8, 2012 at 15:30

Tom Wetmore

2331 silver badge6 bronze badges

1 Comment

tagyro Over a year ago

I'm reading some nodes from a json and I use the node names as variables in my application. I do this because I have for each node three similar names (node, node_waiting, node_rejected) so I'm hopping to use the variable name in such a way that I don't have to create 3 times the number of variables.

Collectives™ on Stack Overflow

Convert variable name to string

3 Answers 3

Comments

Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related